USRA Stock Car rules

Both bumpers are required. Rule 1.8 allows stock-appearing plastic nose and tail pieces, and rule 15.15 conflicts with that; see Body and panels. (Rules 1.15, 1.8, 15.15, Diagram A)

Nose

• Rule 1.8 Nose width: 74 in max, as installed. (Rule 1.8)
• Rule 1.8 Skirting. You can add skirting (a strip along the bottom edge) of up to 3 in to the nose and tail pieces. (Rule 1.8)
• Rule 1.8, Diagram K Ground clearance. The nose, skirting included, must stay at least 8 in off the ground. (Rule 1.8, Diagram K)
• Rule 1.2 With the fabricated 1988 Monte Carlo panels, the only nose and tail allowed are the 1988 Monte Carlo pieces (see Doors and sides). (Rule 1.2)

Bumpers

• Rule 1.15 Edges. No sharp edges on either bumper. (Rule 1.15)
• Rule 1.15 Tubular bumpers. Allowed front, rear or both. Bend them to fit, round the ends and cover them with the molded plastic nose or tail. (Rule 1.15)
• Diagram G Diagram G says a bumper that isn't inside the nose or tail piece must be capped to the body. (Diagram G)

• Rule 1.15 Mounting. Mount each bumper frame end to frame end. (Rule 1.15)
• Rule 1.15 Height. The center of the frame and bumper sits between 16 and 21 in off the ground. (Rule 1.15)
• Rule 1.15 No part of either bumper can be lower than 12 in off the ground. (Rule 1.15)
• Rule 14.3.4 No ballast on the rear bumper. (Rule 14.3.4)

Bars ahead of the radiator

• Rule 2.11 Radiator bars. You can run up to 2 bars in front of the radiator to protect it. They go behind the front bumper, inside the body, and no wider than the stock frame horns (the front ends of the frame rails, ahead of the radiator). (Rule 2.11)
• Rule 2.11 You can tie the front frame horns together. (Rule 2.11)
• Rule 2.11 Every front and rear bar stays inside the body. No adjustable bars on the frame or the cage. (Rule 2.11)
• Rule 2.14 Tow hooks. A tow hook is required at the front and at the rear. (Rule 2.14)

Run a stock steel hood or an aluminum one. You can gut it (remove the inner structure and trim and keep the outer skin). (Rule 1.3, Diagram F)

Hood

• Rule 1.3 One piece. The hood is one piece and separate from the fenders. No one-piece or tilt front ends (hood and fenders built as one unit). (Rule 1.3)
• Rule 1.3 Sealing. Seal the hood to the cowl (the panel between the hood and the windshield). (Rule 1.3)
• Rules 1.9, 1.3 No spoilers or hood scoops, except the air filter shield or scoop described below. (Rules 1.9, 1.3)

Air cleaner and scoops

• Rule 1.3 Hood hole. You can cut a hole in the hood, only to clear the air cleaner, and no bigger than the air cleaner's diameter. (Rule 1.3)
• Rule 1.3 Air cleaner height: 4 in max above the hood. (Rule 1.3)
• Rule 1.3 Air filter shield. On top of the hood, on the front side of the filter, you can add a shield or scoop up to 4 in tall that wraps no more than 180 degrees around the filter. (Rule 1.3)
• Rule 13.6 Under the hood, no shield of any kind can wall off the carburetor or air cleaner. (Rule 13.6)

Engine placement

• Rules 3.7, 3.5 Location. The motor sits in the stock location (where the factory put it). You can't alter the frame or crossmembers to move it. (Rules 3.7, 3.5)
• Rules 3.7, 3.5 Chevy in a metric frame. On a GM 1978-1987 metric frame (GM's mid-size rear-drive perimeter frame), or the Speedway replacement frame built to that pattern, with a Chevy motor, the fuel pump stays ahead of the crossmember, 1.75 in from the crossmember to the center of the pump. (Rules 3.7, 3.5)

• Rule 3.7 Ford. With a Ford engine, the rear of the block sits no more than 22.5 in behind the front of the crossmember. (Rule 3.7)
• Rule 3.7 Chrysler. With a Chrysler block, no more than 21.75 in. (Rule 3.7)

Fenders, doors and quarter panels (the body sides behind the doors) are steel, apart from a few aluminum and fabricated panels allowed by name. (Rules 1.2, 1.1)

Doors and quarter panels

• Rule 1.1 Shape. Fenders, doors and quarter panels keep the OEM (original factory) shape and arc. No flat-sided bodies. (Rule 1.1)
• Rule 1.1 Front fenders. Keep the OEM size and body curve. (Rule 1.1)
• Rule 1.1 Steel Chrysler 300 and steel Camaro fenders are allowed on G-body cars (GM's 1978-88 rear-drive mid-size cars, such as the Monte Carlo, Cutlass Supreme, Regal and Grand Prix). (Rule 1.1)
• Rules 1.1, 1.2 Aluminum parts. Five Star Bodies aluminum lower front fenders (#601-23A) and Five Star Bodies aluminum doors (#601-21A) are allowed. (Rules 1.1, 1.2)
• Rules 1.1, 1.2 Fabricated fenders aren't allowed, except the 1988 Monte Carlo option. (Rules 1.1, 1.2)
• Rule 1.2 1988 Monte Carlo option. You can run fabricated front fenders, doors and lower quarter panels made as 1988 Monte Carlo parts. They must meet the body diagram measurements for this option, and the nose and tail that go with them are under Nose and bumpers. (Rule 1.2)

• Rule 13.8.4 Exhaust. No exhaust out through the body panels or fenders. (Rule 13.8.4)

Skirts and ground clearance

• Rule 1.8, Diagram B Skirts. You can add skirts along the bottom of the doors and quarter panels. The body, skirts included, stays at least 4 in off the ground. (Rule 1.8, Diagram B)

Rub rails

• Rule 1.5 Rub rails. Steel rub rails (strips along the body side that take contact) are allowed, no bigger than 1 in by 2 in, mounted flush with the body. They can run from fender well to fender well and along the rear quarter panel. (Rule 1.5)

Door bars and door plate

• Rule 2.13 Door plate. Weld a steel plate, at least 18-gauge (0.049 in), solidly to the outside of the driver-side door bars (the horizontal cage tubes beside the driver). It must stay visible for inspection. (Rule 2.13)
• Rule 2.13 The plate covers from the top door bar down to the rocker panel (the sill under the doors), and from the rear down post (the rear down bar of the cage) to 6 in ahead of the seat. (Rule 2.13)

Keep the roof at stock dimensions and slope, the window openings at stock dimensions and every pillar stock, steel and in its stock location. All the glass comes out. (Rules 1.2, 1.7, 1.12, Diagram D)

Roof

• Rule 1.2 G-body cars can run an aftermarket fiberglass OEM replacement roof (a copy made to the factory pattern). (Rule 1.2)

Pillars and windshield

• Rule 1.2 Pillars. You can move the driver-side B-pillar (the roof pillar at the back of the door) to get the driver in and out. (Rule 1.2)
• Diagram E B-pillar trim. Diagram E says B-pillars can be trimmed, to no less than 2 in. (Diagram E)

• Rule 1.6, Diagram J Windshield bars. At least 3 windshield bars in front of the driver. (Rule 1.6, Diagram J)

Windows and visors

• Rule 1.7, Diagram D Sun visor. You can add a metal sun visor of up to 7 in at the top of the windshield opening. No visors in the door openings or side windows. (Rule 1.7, Diagram D)
• Rule 1.7 Opera windows. You can cover the rear opera window (the small rear side window on some coupes) with clear Lexan (polycarbonate sheet) only, the same on both sides. (Rule 1.7)

Window net

• Rule 15.13 A full-size window net is required in the driver's window opening on the left side, with its mounts welded to the roll cage. (Rule 15.13)

The trunk lid and quarter panels slope down to the back of the car. (Rule 1.10)

Trunk lid

• Rules 1.10, 1.9 Trunk lid. No concave trunk lids, and no spoilers on the trunk lid or anywhere else on the car. (Rules 1.10, 1.9)

Tail piece

• Rules 1.8, 15.15, Diagram A Tail piece. Rule 1.8 allows a stock-appearing plastic tail piece, and rule 15.15 conflicts with that; see Body and panels. Tail skirting is under Nose and bumpers. (Rules 1.8, 15.15, Diagram A)
• Rule 1.8, Diagram B Tail height. The back of the tail piece and the rear of the deck lid (the trunk lid) can be no more than 20 in above the center of the bumper and frame rails. (Rule 1.8, Diagram B)

Fuel cell and rear firewall

• Rule 7.4.2 Fuel cell. Fasten the cell securely inside the trunk, above the level of the stock trunk floor, with at least 2 solid steel straps around it, each 1/8 in thick and 2 in wide. (Rule 7.4.2)

• Rules 7.4.3, 7.4.5 The steel container, the mounts and the rest of the fuel cell rules are under Fuel, fuel cell and fuel lines. (Rules 7.4.3, 7.4.5)
• Rule 7.4.4 Rear firewall. A firewall goes between the driver and the fuel cell and runs from quarter panel to quarter panel. (Rule 7.4.4)

The dash, the seat back, the rear cage hoop, the speaker deck (the tin shelf behind the seat) and the 12 in firewall setback are all measured back from the rear of the engine. (Rules 4.5, 4.7.3, 2.7, 4.4, 1.11)

Firewall and floor

A fabricated firewall and floor are 18-gauge (0.049 in) steel welded solidly to the frame. Shape the floor like a factory floor pan. If you're building from a donor car, you can keep the factory firewall and floor, or cut them out and replace them this way. (Rule 1.11)

• Rule 1.11 Front firewall. At least 24 in tall. A built firewall can be flat. (Rule 1.11)
• Rule 1.11 Setback. Set it back no farther than the first factory frame seam or 12 in behind the back of the motor. The seam is where the C-channel (a frame rail with a C-shaped cross section) is welded to the front stub (the front section of the frame). (Rule 1.11)

• Rule 4.4 If you build interior tin (sheet metal that forms the cockpit), you still need a full front firewall, but you can leave out the floor pan under the tin. If you're building from a donor car, that means you can cut out the factory floor pan under the tin. (Rule 4.4)
• Rule 7.4.4 The rear firewall, between the driver and the fuel cell, is under Trunk and tail. (Rule 7.4.4)

Dash and interior sheet metal

• Rule 4.5, Diagram H Dashboard. No more than 36 in back from the back of the engine block. Keep the dash flat and level, except for a raised dash cowl right in front of the driver (part of the dash, not the body cowl at the base of the windshield). (Rule 4.5, Diagram H)
• Rule 4.4 Interior tin. Optional. Sheet metal can run from the passenger door to no farther left than the left side of the driveshaft tunnel, and from the dash or firewall back to the rear of the seat. (Rule 4.4)
• Rule 4.4 Tin height. No higher than the top of the door and no lower than the top of the top door bar, level front to back and side to side. (Rule 4.4)
• Rule 4.4 If the tin only runs from the top of the door to the right-side door bar, it can slope down to that bar. (Rule 4.4)
• Rule 4.4, Diagram I Speaker deck. The rear speaker deck can run straight across, quarter panel to quarter panel, back from the driver's seat or from the rear of the interior tin. It stops at the C-pillar (the rear roof pillar) or at 99 in behind the back of the engine, whichever comes first, and can't sit higher than the deck lid or the opera window. (Rule 4.4, Diagram I)
• Rule 4.4 From the back of the C-pillar or the 99 in mark, whichever comes first, everything behind slopes downhill to the back of the car. (Rule 4.4)
• Rule 4.4 The penalty for a speaker deck that runs past the 99 in mark is under Cockpit and seat. (Rule 4.4)

Seat position

• Rule 4.7.3 Seat back. No more than 72 in behind the rear of the engine block. Seat mounting is under Cockpit and seat. (Rule 4.7.3)

Cage-to-body fit

These cage dimensions set the room the body has to fit around. The rest of the cage rules are in the Roll cage section. (Rules 2.4, 2.5, 2.7)

• Rule 2.4 Hoop width. The front and rear hoops are welded to the frame and at least 47 in wide, outside to outside. (Rule 2.4)
• Rule 2.5 Down bar spacing. At least 40 in between the front and rear down bars (the cage tubes from the halo to the frame), measured at the top of the door panel. (Rule 2.5)
• Rule 2.7 Rear hoop. No more than 76 in from the back of the engine to the front edge of the rear hoop. (Rule 2.7)
• Rule 2.7 Halo. The top halo (the top hoop of the cage over the driver) is at least 40 in left to right and 29 in front to back, outside to outside. (Rule 2.7)

Build on a stock frame with no changes, or on the Speedway replacement frame. GM unibody cars are allowed too (see Unibody cars), and the rules for converting a street car are under Donor cars. (Rules 3.5, 3.1)

Which frame

• Rule 3.5 Frame. Use a stock OEM frame, unaltered, or the unaltered Speedway OEM replacement frame (#91678880), Speedway Motors' new-built copy of the GM metric frame. (Rule 3.5)
• Rules 1.1, 3.1 Frame types. The car can sit on a full frame (a separate frame that runs around the car under the body) or be a unibody (body and frame are one welded structure). (Rules 1.1, 3.1)
• Rule 3.10 Titanium. No titanium parts anywhere on the car. (Rule 3.10)

Allowed frame changes

• Rules 3.5, 3.11, 3.4 Apart from the X-bracing and rear frame replacement below, and shortening a Ford full frame under a Ford unibody (see Unibody cars), no changes to the frame or crossmembers, not even for engine placement or suspension clearance, and no widening. (Rules 3.5, 3.11, 3.4)
• Rules 3.9, 3.8 You can X-brace the frame. Suspension parts can't mount to the bracing. (Rules 3.9, 3.8)
• Rule 3.6 Rear frame. Behind the rear tires, you can replace the rear of the frame in the stock location with 2 in by 3 in steel tubing with a 0.095 wall. Start no farther forward than 1 in behind the factory seam. (Rule 3.6)
• Rule 3.6 Leave the factory seam visible, and put back the same length of material you cut out. (Rule 3.6)

Donor cars

A donor car is a street car whose body and frame you convert into the race car.

• Rule 3.3 If you're building from a GM donor car, use a frame of the same year and make as the body, so it matches the factory floor pan and firewall. (Rule 3.3)

Unibody cars

• Rules 3.1, 3.2 GM unibodies. Allowed, with the same 107.5 in minimum wheelbase. (Rules 3.1, 3.2)
• Rule 3.4 Ford unibodies. If you're building from a 1980 or newer Ford unibody car, you can put it on a Ford full frame instead. That frame can be shortened to no less than 111.5 in. (Rule 3.4)

• Rule 3.8 Leaf springs. If you're building from a unibody car with rear leaf springs, you can under-sling the rear end (mount the axle housing below the springs). (Rule 3.8)

Hanging the body

• Rule 1.1 Centered and square. Center the body on the frame and keep it parallel to the frame, front to rear and side to side. (Rule 1.1)
• Rule 1.13 Mounts. Hang the body at the frame's stock body mount locations. (Rule 1.13)
• Rule 1.16 Front-drive bodies. If you put a newer body from a front-wheel-drive car on an older chassis, square it up on the frame. Don't offset it to the left. (Rule 1.16)

Wheelbase, ride height and weight

• Rule 3.2, Diagram C Wheelbase. Center of the front hub to center of the rear hub: at least 107.5 in on both sides, with no more than 1 in difference side to side. (Rule 3.2, Diagram C)
• Rule 3.12 Ride height. The frame sits between 5 and 10 in off the ground, measured behind the front tires and in front of the rear tires, with the driver in the car. (Rule 3.12)
• Rules 14.2, 1.1 Weight. At least 2,900 lb. With the Five Star MD3 Camaro body, at least 2,950 lb. The full weight and ballast rules are in Weight and ballast. (Rules 14.2, 1.1)

Run a 1960 or newer, U.S.-made, full-body passenger car body, on a full frame or a unibody. No panel vans and no station wagons. (Rule 1.1)

Allowed bodies and kits

• Rules 3.3, 1.1, 1.2, 1.3 Steel bodies. The body is a steel OEM body, or an aftermarket steel body made as a stock OEM replacement. Anything else has to be allowed by name: the MD3 Camaro kit below, the fabricated 1988 Monte Carlo panels under Doors and sides and the parts listed under Panel materials. (Rules 3.3, 1.1, 1.2, 1.3)
• Rule 1.1 Five Star MD3 Camaro. The Five Star Bodies MD3 Camaro body (#33131-10200) is allowed, with the 2,950 lb minimum weight under Frame and stance. Don't mix parts from this kit with OEM body parts. (Rule 1.1)
• Rule 1.1 Body lines. The body keeps its OEM body lines and shape. (Rule 1.1)

Panel materials

• Rule 1.2 Steel. Body panels are steel OEM panels or OE replacement panels (copies made to the factory pattern), steel all the way down to the frame. (Rule 1.2)
• Rules 1.3, 1.2, 1.1 Named exceptions. Not steel: an aluminum hood, the Five Star aluminum doors and lower front fenders and a fiberglass OEM replacement roof on G-body cars. Not OEM: the Five Star MD3 Camaro body and the fabricated front fenders, doors and lower quarter panels of the 1988 Monte Carlo option. (Rules 1.3, 1.2, 1.1)
• Rules 15.15, 1.7 Plastic. Rule 15.15 bans plastic anywhere except from the edge of the firewall to the body skin, and from the inner wheel tub to the body skin. The clear Lexan opera window covers that 1.7 allows by name are also allowed. (Rules 15.15, 1.7)
• Rule 1.8 Rule 1.8 allows stock-appearing plastic nose and tail pieces. (Rule 1.8)

Cutting and gutting

• Rule 1.4 Cutting. You can cut the body only to fit the roll cage or to clear the tires. (Rule 1.4)
• Rule 1.13 Gutting. Body panels keep their original size, but you can gut them. (Rule 1.13)

Damage

• Rule 1.14 Officials can keep a car with excessive body damage from racing. (Rule 1.14)

Numbers and appearance

• Rule 1.17.1 Numbers. Every car carries large, readable numbers on both sides, on the roof, on the nose and on the rear panels. (Rule 1.17.1)

• DST fix Typo Official text: nose and real panels → Fixed: nose and rear panels (Rule 1.17.1)

• Rule 1.17.1 Side numbers. These should contrast with the body color and be at least 18 in tall and 4 in thick (the width of each stroke). (Rule 1.17.1)

• Rule 1.17.1 Roof numbers. These should be at least 24 in tall and 4 in thick. (Rule 1.17.1)
• Rule 1.17.2 Advertising. Officials can assign, approve or turn down any advertising, sponsorship or similar deal tied to an event, for the public image of the sport or of USRA. (Rule 1.17.2)
• Rule 1.17.2 Neat cars. Every car must look neat, and officials approve each car to race. By racing, you agree to follow their decisions on this. (Rule 1.17.2)

Run a 4-post cage built from continuous hoops, with the front and rear hoops welded to the frame. Officials have to accept the installation and the workmanship. (Rules 2.3, 2.4)

Tubing and welding

• Rule 2.1 Main cage and door bars. Tubing at least 1.666 in diameter, with at least 0.095 in wall. (Rule 2.1)
• Rule 2.8 Rear kickers and rear hoop X-brace. Kickers are the diagonal braces from the rear hoop toward the back of the frame. Both use at least 1.25 in tubing with 0.083 in wall. (Rule 2.8)
• Rule 2.1 No offset cages. (Rule 2.1)
• Rule 2.1 No aluminum or other soft metals in the cage. (Rule 2.1)
• Rule 2.1 Every roll bar joint must be properly welded. (Rule 2.1)

Hoops and halo

• Rule 2.4 Front and rear hoops: at least 47 in wide, left to right, measured outside to outside. (Rule 2.4)
• Rules 2.7, 2.12 Top halo. The halo is the top hoop of the cage over the driver. It must be at least 40 in left to right and 29 in front to back, outside to outside, with at least 1 cross bar. (Rules 2.7, 2.12)
• Rule 2.5 Down bars. These are the cage tubes from the halo down to the frame. Tie the front down bars together, and keep at least 40 in between the front and rear down bars, measured at the top of the door panel. (Rule 2.5)
• Rules 2.5, 2.7 Rear hoop. X-brace it, and keep its front edge no more than 76 in behind the back of the engine. (Rules 2.5, 2.7)
• Rule 2.6 With the helmet on and the driver belted into the seat, the top of the driver's head can't stick up above the cage. (Rule 2.6)

Door bars and door plate

• Rule 2.9 3 horizontal door bars on each side. (Rule 2.9)
• Rule 2.10 Uprights from the frame to the top door bar: at least 4 on the driver's side and 3 on the passenger side. (Rule 2.10)
• Rule 2.13 Door plate. Weld a steel plate, at least 18-gauge (0.049 in), securely to the outside of the driver's side door bars. (Rule 2.13)
• Rule 2.13 The plate covers from the top door bar down to the rocker panel (the sill under the doors), and from the rear down post forward to 6 in ahead of the seat. (Rule 2.13)
• Rule 2.13 Leave the plate where officials can see it at inspection. (Rule 2.13)

Front bars and tow hooks

• Rule 2.11 You can run up to 2 bars in front of the radiator to protect it. They go behind the front bumper, inside the body, and can't be wider than the stock frame horns (the front ends of the frame rails). (Rule 2.11)
• Rule 2.11 You can tie the front frame horns together. (Rule 2.11)
• Rule 2.11 Every front and rear bar has to stay inside the body. (Rule 2.11)
• Rule 2.11 No adjustable bars on the frame or the cage. (Rule 2.11)
• Rule 2.14 A tow hook is required at the front and at the rear. (Rule 2.14)

• DST fix Bad reference Official text: 3.14 → Fixed: 2.14 (Rule 2.14)

Padding

• Rule 2.2 Pad every roll bar the driver can reach with a material an official accepts. Fire-retardant padding is highly recommended. (Rule 2.2)
• Rule 15.13 The safety rules also call for approved padding on all bars around the driver. (Rule 15.13)

Wear your helmet and fire suit, and be belted into at least a 5-point harness, any time the car is on the track: track packing, warmups, hot laps and races. (Rule 15.3)

Helmet, suit and gloves

• Rule 15.4 Helmet. Required, and certified SA2015, SA2020 or SA2025. (Rule 15.4)
• Rule 15.5 Your helmet has to be with you and the car at inspection. (Rule 15.5)
• Rule 15.6 Fire suit. A complete flame-retardant suit, one-piece or two-piece, is required. (Rule 15.6)
• Rule 15.7 Gloves and shoes. Fire-resistant gloves and shoes are required. Fire-resistant socks are recommended. (Rule 15.7)
• Rule 15.14 Neck collar. A fire-resistant safety neck collar is required. (Rule 15.14)

Belts and harness

• Rule 15.8 Use a 5-, 6- or 7-point restraint system: lap belts, a sub-belt (the strap that runs between the legs) and a shoulder harness. A 7-point system is recommended. (Rule 15.8)
• Rule 15.8 No factory-type shoulder belts or straps. (Rule 15.8)
• Rule 15.9 Metal-to-metal buckles on the shoulder belts and seat belts. (Rule 15.9)
• Rule 15.10 Mount the shoulder harness securely to the roll cage. (Rule 15.10)
• Rule 15.11 Where a belt passes through the edge of the seat, fit a grommet there, rolled, padded or both, so the edge can't cut the belt. (Rule 15.11)
• Rule 15.12 The restraint system must be less than 3 years past its date of manufacture. No more than 2 years is recommended. (Rule 15.12)

Window net and padding

• Rule 15.13 A full-size window net is required in the driver's window opening on the left side. Weld the net mounts to the roll cage. (Rule 15.13)
• Rule 15.13 Every bar around the driver needs approved roll bar padding. (Rule 15.13)
• Rule 15.13 Approved racing arm restraints are recommended. (Rule 15.13)

Fire extinguishers

• Rule 15.2 In the pit. You should keep a fully charged dry chemical or Halon (or equivalent) fire extinguisher in your pit area at all times. A 10 or 13 lb extinguisher is recommended. (Rule 15.2)
• Rule 15.1 In the car. A built-in fire system is recommended. If you fit one, it can't be the dry powder type: use Halon 1211 or equivalent. (Rule 15.1)

The dash, the seat back and the rear speaker deck are all measured back from the back of the engine block. (Rules 4.4, 4.5, 4.7.3)

What can't be in the cockpit

• Rules 4.1, 14.3.1 No loose objects and no weights in the cockpit. Ballast can't go in the cockpit either; where it can go is under Weight and ballast. (Rules 4.1, 14.3.1)
• Rule 4.2 No air bags. (Rule 4.2)
• Rule 4.3 No rear-view mirrors. (Rule 4.3)

Interior sheet metal and speaker deck

Interior tin is optional. If you use it, it can run from the passenger door to no farther left than the left side of the driveshaft tunnel, and from the dash or firewall back to the rear of the racing seat. (Rule 4.4)

• Rule 4.4 Height: no higher than the top of the door and no lower than the top of the top door bar. (Rule 4.4)
• Rule 4.4 Keep it level side to side and front to back. If the tin only runs from the top of the door over to the right side door bar, it can slope down to that bar. (Rule 4.4)
• Rules 4.4, 1.11 With interior tin. You still need a full front firewall, either the factory one or one you built under the firewall and floor rules. You can leave the floor pan out under the tin without replacing it; the rest of the floor follows the firewall and floor rules. (Rules 4.4, 1.11)
• Rule 4.4 Rear speaker deck. The tin behind the seat can run in a straight line from quarter panel to quarter panel, starting at the driver's seat, or at the rear of the interior tin if you have it. A quarter panel is the body side behind the door. (Rule 4.4)
• Rule 4.4 The speaker deck can't go back past the C-pillar (the rear roof pillar) or past 99 in from the back of the engine, and can't sit higher than the deck lid (the trunk lid) or the opera window (the small rear side window on some coupes). (Rule 4.4)
• Rule 4.4 From the back of the C-pillar or the 99 in mark, whichever comes first, everything has to slope downhill to the back of the car. (Rule 4.4)
• Rule 4.4 Penalty. If the speaker deck runs past 99 in, you have to add at least 25 lb of lead on the right front cage hoop, ahead of the shock and spring location, until it's repaired. (Rule 4.4)

Dashboard

• Rule 4.5 The dash can reach no more than 36 in back from the back of the engine block. (Rule 4.5)
• Rule 4.5 It must be flat and level, except for the cowl, a raised part of the dash in front of the driver. (Rule 4.5)

Seat

• Rules 4.7.1, 4.7.2 Use a factory-built racing seat that officials accept. No homemade aluminum, plastic or fiberglass seats. (Rules 4.7.1, 4.7.2)
• Rule 4.7.4 High-back aluminum seats only. A full containment seat is strongly recommended. (Rule 4.7.4)
• Rule 4.7.3 Mount the seat with at least 3/8 in fasteners and washers. (Rule 4.7.3)
• Rule 4.7.3 The seat back can sit no farther back than 72 in from the rear of the engine block. (Rule 4.7.3)

Use OEM steering (original factory parts), made of steel and matched to your frame, and keep it within the original bolt pattern for that type of frame. (Rules 4.6.1, 5.3, 5.8)

• Rule 4.6.1 Steering linkage: unaltered, approved OEM, in the stock location, replaceable with a stock part and matched to the frame. (Rule 4.6.1)
• Rule 4.6.1 You can use steel tube tie rod adjusting sleeves. (Rule 4.6.1)
• Rule 4.6.2 No rack and pinion. (Rule 4.6.2)
• Rule 4.6.3 Inside the cockpit, you can change the steering to fit the driver, as long as it stays on the left side. No center steering. (Rule 4.6.3)
• Rule 4.6.4 A metal quick-release coupling on the steering wheel is required. No plastic couplings. (Rule 4.6.4)

Suspension parts must be factory (OEM) parts that match your frame, unless a rule below allows something else. (Rule 5.1)

Materials

• Rule 5.8 Use steel for every suspension, steering and rear end part. (Rule 5.8)
• Rules 5.1, 5.6, 5.11.5 No aluminum or titanium parts, and a magnet has to stick to every component. The exceptions are the aluminum cross shaft on upper A-frames and the aluminum shaft guide on a shock. (Rules 5.1, 5.6, 5.11.5)
• Rule 5.9 No hollow, tubular or gun-drilled bolts or studs anywhere on the car. (Rule 5.9)

Front end

• Rule 5.3 Ball joints. OE and non-adjustable. (Rule 5.3)
• Rule 5.4 Spindles. Stock passenger car spindles only, matched to the frame. No fabricated spindles. (Rule 5.4)
• Rule 5.5 Lower A-frames. They can't be altered or moved, and they must match the frame. (Rule 5.5)
• Rule 5.6 Upper A-frames. Tubular upper A-frames are allowed, with or without an aluminum cross shaft, adjustable or not. You can move the upper A-frame mounts. (Rule 5.6)

Rear control arms and bushings

• Rule 5.6 Rear control arms can be aftermarket, but they must keep legal bushings and OEM length and mount to the frame in the OEM location. (Rule 5.6)
• Rule 5.7 No offset or bearing-type bushings in the rear control arms or the front lower A-frames. (Rule 5.7)
• Rule 5.7 No mono-ball or heim-style bushings. Bushings must be one-piece, made of steel, rubber, polyurethane or nylon. (Rule 5.7)
• Rule 5.7 Bushing material must be solid and as wide as the inner sleeve. (Rule 5.7)
• Rule 5.7 The inner steel sleeve must be in place and OEM length. (Rule 5.7)
• Rule 5.7 No fore-and-aft movement in the bushing. (Rule 5.7)

Weight jacks and leaf springs

• Rule 5.2 Weight jacks (adjusters that raise or lower a spring seat to shift corner weight) are optional. Any device that lets the driver change the wheelbase or jack weight while the car is in competition is strictly banned. (Rule 5.2)
• Rule 5.2 Leaf spring cars can use leaf spring sliders on the rear of the leaf spring only. Front leaf spring mounts stay stock and in the stock location. (Rule 5.2)
• Rule 3.8 Under-slinging the rear end on unibody leaf spring cars is under Frame and stance. (Rule 3.8)

Tether chains

• Rule 5.10 You can run a tether chain on the front and rear suspension. (Rule 5.10)
• Rule 5.10 Front: from the lower A-frame to the frame or cage. Rear: from the top of the axle tube to the frame or cage. (Rule 5.10)
• Rule 5.10 Mount the chains vertically and solidly, and keep them loose at ride height. (Rule 5.10)
• Rule 5.10 No rubber biscuits. (Rule 5.10)

Racing shocks and springs are allowed. Each wheel gets 1 unaltered, non-adjustable, steel-bodied shock. (Rule 5.11.5)

Shocks

• Rule 5.11.1 Front. Mount front shocks to the upper or lower A-frame. (Rule 5.11.1)
• Rules 5.11.2, 5.11.4 Rear. Mount the rear shocks behind the rear-end housing, within 2 in of the centerline of the lower control arm bracket on the rear end, and within 25 degrees of vertical. You can move them, as long as they still meet all 3 of those conditions. (Rules 5.11.2, 5.11.4)
• Rule 5.11.2 The top of a rear shock can mount on an adjustable weight-jack-type bolt. (Rule 5.11.2)
• Rule 5.11.3 No sliding shock mounts and no coil-over eliminators. (Rule 5.11.3)
• Rule 5.11.6 No coil-over, remote reservoir or air reservoir shocks. (Rule 5.11.6)
• Rules 5.11.7, 5.11.5 No bladder-type valves. Schrader valves are allowed. (Rules 5.11.7, 5.11.5)
• Rule 5.11.5 An aluminum shaft guide on the shock end is allowed. (Rule 5.11.5)
• Rule 5.11.5 No bump stops, inside or outside the shock, no other suspension stops and no travel-limiting devices. (Rule 5.11.5)
• Rule 5.11.5 The shaft must compress all the way into the shock body. (Rule 5.11.5)
• Rule 5.11.5 Measured at ride height, the shaft must be able to move in both directions from its installed position. (Rule 5.11.5)
• Rule 5.11.5 The shock can't preload the spring. (Rule 5.11.5)
• Rule 5.11.8 Shocks can be protested. The procedure is under Protests. (Rule 5.11.8)

Springs

• Rule 5.11.10 No progressive springs and no spring rubbers. (Rule 5.11.10)
• Rule 5.11.9 No widgets, spring-loaded cups or double spring cups. (Rule 5.11.9)
• Rule 5.11.11 Mount springs straight up and down, not tipped. (Rule 5.11.11)
• Rule 5.11.11 Rear springs can't sit past the centerline of the rear-end housing. (Rule 5.11.11)
• Rule 5.11.11 Weld the lower spring perches solid to the rear-end housing. No pivoting perches. (Rule 5.11.11)
• Rule 5.11.11 Spring tethers are allowed. (Rule 5.11.11)
• Rule 5.11.12 No spring or suspension covers. (Rule 5.11.12)

The brakes must work on all 4 wheels, and at inspection they must lock all 4. (Rule 9.1)

• Rule 9.2 Calipers and rotors. Rule 9.2 calls for steel OEM (original factory, also written OE) calipers and steel vented rotors on all 4 wheels. (Rule 9.2)
• Rule 9.4 Drums. Rule 9.4 calls for a working OE 4-wheel brake setup, drum or disc, so it allows drums. (Rule 9.4)

• Rule 9.2 Matching. The 2 front calipers must match each other, and so must the 2 rears. Pads must match side to side. (Rule 9.2)
• Rule 9.5 Rotor rules. Stock vented rotors only. No scalloped rotors, and rotors can't be lightened. (Rule 9.5)
• Rule 9.5 No floating brakes (calipers on a bracket that pivots around the axle, held by a link to the chassis). (Rule 9.5)
• Rule 9.8 Sizes. Hubs, rotors, pads and calipers can't be smaller than the OEM dimensions. (Rule 9.8)
• Rule 9.6 Lines. Run the brake lines outside the frame rails, where they can be seen. (Rule 9.6)
• Rules 9.3, 9.7 Controls. No electronic brake actuators, no brake shut-offs and no pressure-sensitive devices. You can run 1 proportioning device, front to rear only. (Rules 9.3, 9.7)

Wheels are reinforced steel, 15 in diameter and 8 in wide, and the only tire is the American Racer G60-15 KK704. (Rules 8.1.1, 8.1.3, 8.2.1)

Wheels

• Rule 8.1.2 Lug nuts. Steel lug nuts only. (Rule 8.1.2)
• Rule 8.1.4 Bead locks. A steel bead lock is allowed on the right-side wheels only. It can mount on the outside of the wheel as long as the wheel ends up no wider. (Rule 8.1.4)
• Rule 8.1.7 Spacers and offset. You can use a spacer or adapter, an offset wheel or a mix of the two. Spacers and adapters must be aluminum, and the total offset is no more than 2 in per wheel. (Rule 8.1.7)
• Rules 8.1.5, 8.1.8 Mud caps. A mud cap is a cover over the outside of the wheel that keeps mud out. No homemade mud caps. You can weld up to 3 tabs to a wheel to mount one, each no more than 2 in long. (Rules 8.1.5, 8.1.8)
• Rule 8.1.6 Wheel covers. Right-side wheels only. You can run inner mud plugs. (Rule 8.1.6)
• Rule 8.1.9 No bleeder valves. (Rule 8.1.9)
• Rule 8.1.10 No added ballast on any wheel. (Rule 8.1.10)

Tires

• Rule 8.2.1 Sizes. The Short, Tall and X Tall versions of the KK704 are all legal. (Rule 8.2.1)
• Rule 8.2.1 Hardness. At the end of any race, every tire must read 50 or harder on a durometer (a tire hardness gauge). A tire that reads softer can have a sample sent off for chemical testing. (Rule 8.2.1)
• Rule 8.2.2 No treatments. No softening and no solvents of any kind. Nothing, chemical or otherwise, that changes the tire from the maker's baseline. (Rule 8.2.2)
• Rule 8.2.3 No ballast inside any tire. (Rule 8.2.3)
• Rule 8.2.4 Cutting. Grooving and siping (thin cuts across the tread) are allowed. (Rule 8.2.4)
• Rule 8.2.5 Markings. Keep the sidewall markings visible. No buffing off or removing the compound markings. (Rule 8.2.5)
• Rule 8.2.6 Plastic wrap. You can wrap tires in plastic in your pit, but take it off before the car leaves your pit stall. (Rule 8.2.6)

Tire testing and penalties

USRA can run random gas chromatography (GC) scans to look for illegal substances. (Rule 8.3.1)

• Rule 8.3.1 A scan should always peak at 19 to 20 minutes. No peak means the driver is disqualified. (Rule 8.3.1)
• Rule 8.3.1 The driver can protest a GC result and ask for a mass spectrometry test, at the driver's cost (about $300). That test shows exactly which substance was used. (Rule 8.3.1)
• Rule 8.3.1 Rule 8.3.1 says the tire's main peak should never be "in half". (Rule 8.3.1)

• Rule 8.3.2 Penalty. Traces of chemicals, or chemicals in amounts outside the baseline, found on any test mean automatic disqualification. (Rule 8.3.2)
• Rule 8.3.2 A first offense costs all season points, all prize money from that event, a fine of up to $5,000 and an indefinite suspension from USRA events. You can't race a USRA event again until the fine is paid in full. (Rule 8.3.2)
• Rule 8.3.3 Strongly recommended: clean tires with soap and water only. Baking a tire won't remove traces of illegal substances. (Rule 8.3.3)

This covers everything from the back of the engine to the rear end: transmission, clutch or flex plate, bell housing, scatter shield and driveshaft.

Transmission

You have 3 choices: an OEM production 3-speed or 4-speed manual, an OEM production automatic or one of the approved aftermarket transmissions listed below. (Rules 11.1, 11.8)

• Rules 11.2, 11.8 Not allowed. No "in and out" boxes (a direct-drive box that is only in or out of gear, with no gears to shift), no 5-speed transmissions and no quick-change devices in the transmission. The approved aftermarket boxes below are legal. (Rules 11.2, 11.8)
• Rule 11.3 Gears. At least 1 forward gear and reverse, plus neutral. With the engine running and the car sitting still, the driver has to be able to put it in gear and drive forward, then back up. (Rule 11.3)
• Rule 11.5 OEM manual. Stock-appearing OE case. (Rule 11.5)
• Rule 11.6 OEM automatic. Stock-appearing OEM automatic case with a working stock-appearing pump. (Rule 11.6)
• Rule 11.8 Approved aftermarket. Bert (#LMZ/GEN II), Brinn (#70001), Brinn Predator (#70600), Falcon (#60100), RaceGator (#140002/140002-C), Jerico (#JER0021) and the Mitchell Machine Bullet Tranny with internal clutch. (Rule 11.8)
• Rule 11.8 No ball spline transmissions (the output shaft and the driveshaft slip yoke ride on ball bearings instead of plain splines). (Rule 11.8)

Clutch, flywheel and bell housing

• Rule 11.4 Flywheel and pressure plate. 1 flywheel only, bolted straight to the end of the crankshaft, with the pressure plate bolted straight to the flywheel. (Rule 11.4)
• Rule 11.4 Everything inside the bell housing must turn whenever the car is in any gear. (Rule 11.4)
• Rule 11.5 OEM manual: clutch and bell housing. A working external disc clutch, at least 6.25 in diameter, inside an explosion-proof steel bell housing. (Rule 11.5)

• DST fix Missing info Official text: six and one-quarter (6.25) diameter → Fixed: 6.25 in diameter (Rule 11.5)

• Rule 11.5 Flex plates. A flex plate must be SFI-certified and can't be lightened. (Rule 11.5)

• DST fix Typo Official text: Lightened flex plates are not allowed and must be SFI certified → Fixed: Flex plates must be SFI-certified and not lightened (Rule 11.5)

• Rule 11.6 OEM automatic: bell housing. Keep the original bell housing. (Rule 11.6)
• Rule 11.8 Aftermarket transmission: bell housing. Run a performance bell housing. Stock aluminum bell housings aren't allowed with these boxes. (Rule 11.8)
• Rule 11.9 Starter. The starter bolts to the engine block in the factory location. (Rule 11.9)

Scatter shield

• Rule 11.7 An approved scatter shield or scatter blanket (a ballistic fabric wrap around the bell housing) is required. (Rule 11.7)
• Rule 11.7 A shield can be made from 0.125 in by 3 in steel, wrapped 270 degrees around the flex plate or flywheel. (Rule 11.7)

Driveshaft

• Rule 10.1 Loop. A driveshaft loop is required: solid steel at least 0.25 in by 2 in, mounted no more than 6 in from the front of the driveshaft tube. (Rule 10.1)
• Rule 10.1 Or run 2 loops of 0.25 in by 1 in solid steel, fastened to the crossmember. (Rule 10.1)
• Rule 10.2 Shaft. Rule 10.2 says the driveshaft must be steel and painted white. (Rule 10.2)
• Rule 10.4 Rule 10.4 allows a carbon fiber driveshaft if it's white and at least 3 in in diameter. (Rule 10.4)

• Rules 10.3, 10.4 Yokes. Steel yokes, except that aluminum yokes are allowed with a carbon fiber driveshaft. (Rules 10.3, 10.4)

Any passenger car or truck rear end is allowed, and so are the Ford 9 in and a quick change. (Rules 12.1, 12.2, 12.5)

Housing, axles and gears

• Rules 12.2, 9.5 Ford 9 in. A floater is recommended: full-floating axles, where the wheel hubs ride on bearings on the axle housing and the axles only turn the wheels. A floater isn't the floating brakes banned under Brakes. (Rules 12.2, 9.5)
• Rule 12.1 Aluminum. No aluminum, except lowering blocks, axle caps, U-joint caps and the drive plate. (Rule 12.1)
• Rule 12.4 Locked rear. Full steel spool, steel mini-spool or a welded rear end only. A spool locks both axles together in place of the differential, and a mini-spool does the same inside the stock carrier. Steel axles only. (Rule 12.4)
• Rule 12.5 Quick change. Axle tubes must be steel too. Use a 10 in ring gear and solid spur gears at least 1 in wide. (Rule 12.5)
• Rule 12.7 No cambered rear ends (a housing built to tilt the wheels in or out). One-piece drive flange only. (Rule 12.7)
• Rule 12.8 No mechanical or electrical traction devices. (Rule 12.8)
• Rule 12.3 Recommended: a 1 in inspection hole in the center section. (Rule 12.3)

Rear suspension and brackets

• Rules 12.3, 5.6, 12.6 Rear suspension. Keep the stock rear suspension design for your frame, with stock parts and stock dimensions. Exceptions: aftermarket rear control arms are allowed at OEM length, with legal bushings, on the OEM frame mounts (see Suspension, Rear control arms and bushings), and so are the adjustable lower brackets below. (Rules 12.3, 5.6, 12.6)
• Rule 12.3 No Panhard bars (a sideways bar from the axle to the frame that locates the rear end). (Rule 12.3)
• Rules 12.6, 5.7 Upper trailing arm brackets. These are the brackets on the rear end for the upper rear control arms (trailing arms). Non-adjustable only, level side to side, and they have to meet the bushing rules under Suspension, Rear control arms and bushings. (Rules 12.6, 5.7)
• Rule 12.6 Lower trailing arm brackets. For the lower rear control arms: the bolt center can sit no more than 7.5 in below the bottom of the axle tube. (Rule 12.6)
• Rule 12.6 Up to 5 separate adjustment holes in each lower bracket. No slotted holes and no removable slugs. (Rule 12.6)
• Rules 5.11.2, 5.11.11 Spring perches and rear shocks. The rules for welding the lower spring perches solid and for mounting the rear shocks are under Shocks and springs. (Rules 5.11.2, 5.11.11)

The car runs a 12-volt system: 1 battery and a 12-volt ignition. No 16-volt batteries and no voltage converters. (Rules 6.1.2, 6.1.3)

Battery and alternator

• Rules 6.1.1, 6.1.4 Mounting. Mount the battery securely between the frame rails and cover it. If it's in the cockpit, it goes in a marine battery box. (Rules 6.1.1, 6.1.4)
• Rule 6.1.5 Every battery post must be securely covered. (Rule 6.1.5)
• Rule 6.1.6 Alternator. Allowed, with 14-volt output at most. Wire it straight to the battery, not to the on/off switch. (Rule 6.1.6)

Ignition

• Rule 6.2.1 No magnetos and no crank-triggered ignitions (timing triggered by a sensor on the crankshaft instead of the distributor). (Rule 6.2.1)
• Rule 6.2.2 1 coil at most. (Rule 6.2.2)
• Rule 6.2.3 Kill switch. You need one, where the driver can easily reach it, clearly marked "OFF" and "ON". (Rule 6.2.3)
• Rule 6.2.4 Ignition box. Mount it where the driver can't reach it. (Rule 6.2.4)

Gauges, data and cameras

• Rule 6.3 No digital gauges, except a digital tachometer. (Rule 6.3)
• Rule 6.3 No cameras aimed at any moving or suspension part. (Rule 6.3)
• Rule 6.3 No electronic monitoring device that can store or send information. The one exception is a memory recall tachometer (a tach that stores the highest rpm for the driver to read back). (Rule 6.3)

Transponder

• Rule 6.4 Mount the transponder standing up (vertical), behind the rear of the engine, less than 2 feet off the ground, with no metal blocking it. (Rule 6.4)

The car is weighed after the event, with the driver sitting in it in full racing gear. (Rule 14.1)

• Rules 14.2, 1.1 Minimum weight. 2,900 lb. A car with the Five Star MD3 Camaro body (#33131-10200) must weigh at least 2,950 lb. (Rules 14.2, 1.1)

• DST fix Missing info The official weight rule doesn't mention the 2,950 lb minimum for the Five Star MD3 Camaro body from 1.1; DST added the cross-reference. (Rule 14.2)

Where ballast can go

• Rule 14.3.4 Allowed spots. Mount ballast to the frame, the roll cage or the rear-end housing only. Brackets for weight on the rear-end housing must be steel. (Rule 14.3.4)
• Rules 14.3.1, 14.3.4 Banned spots. No ballast on the rear bumper, in the cockpit, outside the body or on any rotating or suspension part. (Rules 14.3.1, 14.3.4)
• Rules 14.3.1, 14.3.4 Roll cage in the cockpit. Read one way, ballast can go anywhere on the roll cage, tubes inside the cockpit included. Read the other way, the cockpit ban still applies, so only cage tubes outside the cockpit can carry ballast. (Rules 14.3.1, 14.3.4)

• Rule 14.3.1 Hood area. Rule 14.3.1 can be read 2 ways: no ballast anywhere in the hood area (the engine bay), or only no ballast outside the body or hood, which would allow ballast on the frame rails in the engine bay. (Rule 14.3.1)

Mounting ballast

• Rule 14.3.2 Mount it securely, paint it white and mark it clearly with the car number. (Rule 14.3.2)
• Rule 14.3.3 Use at least 2 bolts, 0.5 in, with no more than 100 lb on each mounting. (Rule 14.3.3)
• Rule 14.3.3 A weight of 25 lb or less can mount on 1 bolt, 0.5 in. (Rule 14.3.3)

A licensed driver who meets the conditions below can protest certain parts on 1 of the top 4 cars, in the tech area right after the main event. (Rules 16.1, 16.2, 16.6)

What can be protested, and the cost

• Rule 16.1 Parts. Cylinder heads and intake manifold, shocks or carburetor. (Rule 16.1)
• Rule 13.9.5 Sealed crate engines. A factory-sealed GM 604 crate engine can't be protested, unless its driver protested a standard engine and then switched to the sealed crate engine. An unsealed crate engine can be protested. see Option 1: GM 604 crate engine. (Rule 13.9.5)
• Rule 16.5 Cost, in cash. Heads and intake manifold $500. Carburetor $150. Shocks $100, which covers 1 shock or all of them in a single protest. (Rule 16.5)
• Rule 16.5 Hand the cash to the official running the tech area when you declare the protest. (Rule 16.5)
• Rule 16.5 Where the money goes. $50 goes to the track officials. The rest goes to the protested driver if the part is legal, or back to the protesting driver if it's illegal. (Rule 16.5)

Who can protest, and when

• Rules 16.1, 16.9 Who. Only a driver, holding a valid USRA license. (Rules 16.1, 16.9)
• Rule 16.2 You have to finish 5th or lower in the main event, on the same lap as the winner. (Rule 16.2)
• Rule 16.17 You must have raced at least 3 events in a row before the event where you protest. (Rule 16.17)
• Rule 16.19 No protest at an event where you started from a provisional starting spot. (Rule 16.19)
• Rule 13.9.5 If you run a sealed crate engine, you can't protest engines that season. (Rule 13.9.5)
• Rules 16.7, 16.16 How many. 1 protest per event, whatever the outcome, and 3 at most per calendar year. (Rules 16.7, 16.16)
• Rules 16.3, 16.4 When. Within 5 minutes after the main event ends. Drive your own car under its own power straight to the tech area right after the main event. (Rules 16.3, 16.4)
• Rule 16.6 Choosing. Pick 1 of the top 4 finishers and tell the tech area official. If several drivers want to protest, the one who finished farthest back picks first. (Rule 16.6)
• Rule 16.18 USRA can turn down any protest at its discretion. (Rule 16.18)

The tech area

• Rule 16.2 Top 4. The top 4 finishers in the main event drive straight to the tech area after the race. A top 4 car that doesn't go is disqualified, and it can still be protested. (Rule 16.2)
• Rule 16.8 Who's allowed in. Drivers, car owners and officials only. Anyone else tied to a car who comes in can be disqualified, fined, suspended or any mix of these. (Rule 16.8)

• Rule 16.5 Other parts. Officials can still inspect any part they examine during the protest, even one that isn't being protested, and rule it legal or illegal. (Rule 16.5)

Accepting or refusing a protest

• Rule 16.9 Only the protested driver or car owner can accept or refuse. The first answer, yes or no, is final. (Rule 16.9)
• Rule 16.14 If the driver and the owner disagree, the driver's call wins. (Rule 16.14)
• Rule 16.3 Teardown. Once the protest is accepted, the protested parts come off at the track within 1 hour. (Rule 16.3)
• Rule 16.5 Disputes. If anyone disputes the officials' call, the parts go to USRA for a final decision. (Rule 16.5)
• Rule 16.5 Shipping. If officials rule the part illegal and the protested driver disputes it, the protested driver pays. If they rule it legal and the protesting driver disputes it, the protesting driver pays. (Rule 16.5)

Penalties

A driver or car owner who refuses a protest loses all cash and contingency winnings from that event and all USRA points up to and including that event. They also lose the right to protest at any USRA event for 1 year from the refusal. (Rules 16.10, 16.11, 16.12)

• Rule 16.13 First refusal. Driver and car owner are suspended from all USRA events for 30 days, and stay suspended until USRA has received a $1,000 fine. (Rule 16.13)
• Rule 16.13 Second refusal. Driver and car owner are suspended from all USRA events for 1 year, and stay suspended until USRA has received a $5,000 fine. (Rule 16.13)
• Rule 16.15 Protesting for someone else. A driver caught filing a protest for another person loses all USRA points for the season to date and all cash and contingency winnings from that event. The driver is also suspended from all USRA events for 30 days, and stays suspended until USRA has received a $1,000 fine. (Rule 16.15)

You can run any of 3 engines: Option 1, the GM 604 crate engine; Option 2, the 360 engine; or Option 3, the standard engine. The rules in this topic apply to all three, and each option has its own topic after this one. (Rules 13.9, 13.10, 13.11)

Pumps and starting

• Rules 13.2, 7.2 No electric or belt-driven fuel pumps. (Rules 13.2, 7.2)
• Rule 13.3 The car has to start on its own, with no push or pull, and be able to join the lineup unaided whenever it's called. (Rule 13.3)
• Rule 3.7 Engine placement. Where the motor has to sit, with the measurements for Chevy, Ford and Chrysler engines, is under Hood and engine bay. (Rule 3.7)

Cooling

• Rules 13.4, 13.1 You can modify the cooling system. Aluminum water pumps are allowed. (Rules 13.4, 13.1)
• Rule 13.4 1 radiator, mounted ahead of the engine. No sprinkler systems. (Rule 13.4)
• Rule 13.4 Point the overflow tubes at the ground, between the frame rails. (Rule 13.4)

Air cleaner and intake

• Rule 13.6 Top-flow air cleaner housings are allowed. No cold air boxes and no air cleaner ductwork. (Rule 13.6)
• Rules 13.6, 1.3 No shields of any kind to close off the carburetor or air cleaner inside the engine bay. The shield or scoop that rule 1.3 allows on top of the hood is covered under Hood and engine bay. (Rules 13.6, 1.3)
• Rule 13.7 Intake manifolds must be cast iron or cast aluminum. Each option below lists the intakes it allows. (Rule 13.7)

Oil accumulators

• Rule 13.5 Mount accumulators, such as an Accusump (a tank that stores oil under pressure and feeds it back when pressure drops), in the middle of the car or behind the driver, never on the door bars (the horizontal cage tubes beside the driver). (Rule 13.5)

Exhaust

• Rule 13.8.1 Aim the exhaust at the ground, away from the cockpit and away from anywhere fuel could spill. (Rule 13.8.1)
• Rule 13.8.5 Keep dual exhaust. No crossover or Y pipes. (Rule 13.8.5)
• Rules 13.8.4, 13.8.5 Each bank's header pipes run into 1 collector at least 4 in long. (Rules 13.8.4, 13.8.5)
• Rule 13.8.3 No zoomies (open pipes off each exhaust port), no 180-degree headers and no over-the-top headers. (Rule 13.8.3)
• Rule 13.8.4 No exhaust out through body panels or fenders. (Rule 13.8.4)
• Rule 13.8.2 Recommended: mufflers. Some tracks require them. (Rule 13.8.2)

Option 1 is GM's CT400 "604" small block Chevy crate engine from GM Performance Parts (GPP), and no other engine. You can rebuild it and you don't have to keep it sealed, but it must stay unaltered: it's built from the unaltered parts listed below, and it has to meet the rest of this rule. (Rules 13.9, 13.9.1)

• Rules 13.9.4, 7.3.3 Carburetor. You can run 1 Holley 4150 Series four-barrel, as set out under Carburetor. (Rules 13.9.4, 7.3.3)

Parts list

• Rule 13.9.1 Block: CT400 four-bolt-main only. (Rule 13.9.1)
• Rule 13.9.1 Pistons #10159436, GM connecting rods #10108688, cast iron crankshaft #12556307 and GM balancer #88960604. (Rule 13.9.1)
• Rule 13.9.1 Heads: Fast Burn 23-degree aluminum, #12464298. Head gasket: GM #12557236. (Rule 13.9.1)
• Rule 13.9.1 Intake: high-rise manifold #12496822. Valve covers: 604 cover #25534359. (Rule 13.9.1)
• Rule 13.9.1 Cam: the unaltered GM camshaft #10185071, nothing else. (Rule 13.9.1)
• Rule 13.9.1 GM lifters #17120735, GM pushrods #10241740 and GM rocker arms #19210724. (Rule 13.9.1)
• Rule 13.9.1 GM valves #12555331 intake and #12551313 exhaust, GM valve springs #12551483 and GM spring retainers #10212808. (Rule 13.9.1)
• Rule 13.9.1 GM timing gears #12552129/14088784, GM timing chain #14088783 and GM oil pump #14044872. (Rule 13.9.1)
• Rule 13.9.1 Every other gasket on the engine can be any brand. (Rule 13.9.1)
• Rule 13.9.1 The rest of the engine follows the 604 crate engine's specifications. (Rule 13.9.1)

Machine work allowed

• Rule 13.9.1 You can deck the block to a deck height of no less than 9.020 in. (Rule 13.9.1)
• Rule 13.9.1 You can correct the crankshaft line bore (the main bearing bores in the block). (Rule 13.9.1)
• Rule 13.9.1 Cylinder bore: 4.008 in at most. (Rule 13.9.1)
• Rule 13.9.1 Crank journals: no more than 0.010 in under standard size. (Rule 13.9.1)
• Rule 13.9.1 Head resurfacing: 0.005 in at most. (Rule 13.9.1)
• Rule 13.9.1 A standard three-angle valve job is allowed. Valve and seat sizes and angles stay stock. (Rule 13.9.1)
• Rule 13.9.1 No changes below the valve seat land. (Rule 13.9.1)
• Rule 13.9.1 No grinding, polishing, painting or coating of internal engine parts. (Rule 13.9.1)
• Rule 13.9.1 No lifter bore valley vent tubes, and no changes to the lifter bores. (Rule 13.9.1)

Oil pan and sight plug

• Rule 13.9.1 Oil pan: any circle track pan, as long as it's steel, 8-quart and single kickout (the sump bulges out on one side). (Rule 13.9.1)
• Rule 13.9.1 If the engine isn't sealed, the rule requires a 1 in or larger sight plug in the side of the pan, above the oil level. (Rule 13.9.1)
• Rule 13.9.1 The same rule then says that if you don't run a 1 in plug, the pan may have to come off for inspection. (Rule 13.9.1)

Seals and protests

• Rule 13.9.5 A factory-sealed crate engine can't be protested, but it must carry a "Crate" decal near the A-pillar (the windshield pillar), where it's easy to see. (Rule 13.9.5)
• Rule 13.9.5 An unsealed crate engine can be protested. (Rule 13.9.5)
• Rule 13.9.5 If you run a sealed crate engine, you can't protest engines that season. (Rule 13.9.5)
• Rule 13.9.5 If you protest a standard engine and then switch to a sealed crate engine, you can be protested. The procedure is under Protests. (Rule 13.9.5)

Option 2 is a stock-looking engine with a cap on displacement and compression, both under Compression and size. Engines in this option can be protested; the procedure is under Protests. (Rules 13.10, 13.10.1, 13.10.10, 13.10.11, 13.10.18)

Block, crank and rods

• Rules 13.10.1, 13.10.2 The engine must look strictly stock for its make and model, sit in the original mounts and use the stock firing order for its make and model (for example GM to GM or Ford to Ford). (Rules 13.10.1, 13.10.2)
• Rule 13.10.1 No changes beyond what this option's rules allow. No titanium. (Rule 13.10.1)
• Rule 13.10.2 Approved aftermarket blocks: Dart #31161111, Brodix #BRS400035842, GM #12480047 or World Products #084010. (Rule 13.10.2)
• Rules 13.10.2, 13.10.6 No parts from engines of 400 cubic inches or more. The stroke must match the block, and no stroking. (Rules 13.10.2, 13.10.6)
• Rule 13.10.3 Crankshaft: stock-looking only. No lightweight, undercut, bull-nosed, gun-drilled or knife-edged cranks. (Rule 13.10.3)
• Rule 13.10.3 No lightweight, aluminum or fluid harmonic dampers. (Rule 13.10.3)
• Rule 13.10.3 Pistons: flat-top or dished only. (Rule 13.10.3)
• Rule 13.10.4 Rule 13.10.4 says only: no aluminum or lightweight. (Rule 13.10.4)

• Rules 13.10.12, 13.10.14 GM 5.7 in or 6 in rods are allowed. Rods must be stock-looking I-beam, not polished, and cap screw rods are allowed. (Rules 13.10.12, 13.10.14)
• Rule 13.10.12 Standard-size rod journals and wrist pins only; for Chevrolet rods that's 2.100 and 0.927. (Rule 13.10.12)
• Rule 13.10.5 Recommended: a 1 in or larger sight plug in the side of the oil pan, above the oil level. Without one, the pan may have to come off at inspection. (Rule 13.10.5)

Heads

• Rule 13.10.8 Heads: cast iron stock production heads, or unaltered aftermarket steel stock replacement heads. No porting or polishing. (Rule 13.10.8)

• Rule 13.10.8 GM cars must run 76 cc heads. Approved GM head numbers: 336, 339, 388, 441, 454, 487, 624, 813, 882, 991 and 993. (Rule 13.10.8)
• Rule 13.10.8 Approved aftermarket heads for GM: EQ #CC167ES2 or #CH350I, Dart #10024267 or #10024360, World Products #043600 or #042670. (Rule 13.10.8)
• Rule 13.10.8 Approved aftermarket heads for Ford: World Products #53030. For Chrysler: EQ #CH318B, or RHS/Indy #20300 or #20301. (Rule 13.10.8)
• Rule 13.10.8 You can flat-mill the heads to reach the 10.5:1 compression rule. (Rule 13.10.8)
• Rule 13.10.8 Largest valves: 2.02 intake, 1.60 exhaust. (Rule 13.10.8)
• Rule 13.10.8 No Vortec heads. (Rule 13.10.8)

Cam and valve train

• Rule 13.10.9 Cam: a roller cam with hydraulic roller lifters is allowed. A roller cam with solid roller lifters isn't. (Rule 13.10.9)
• Rule 13.10.9 Hydraulic roller lift: no more than 0.525 in measured at the valve "and/or" 0.350 in measured at the cam, as the rule words it. (Rule 13.10.9)

• Rule 13.10.9 Hydraulic roller valve springs: seat pressure no more than 140 lb and open pressure no more than 390 lb, no tolerance. (Rule 13.10.9)
• Rule 13.10.8 Chrysler engines can use OEM (original factory) steel or aluminum shaft rockers, but Chryslers can't go over 120 lb of valve spring seat pressure and must keep OEM valve spring dimensions. (Rule 13.10.8)
• Rules 13.10.8, 13.10.9 No beehive valve springs, and no rev kits (springs that hold the lifters against the cam at high rpm). (Rules 13.10.8, 13.10.9)
• Rules 13.10.9, 13.10.15 Roller rocker arms are allowed. No stud girdles (a bar that ties the rocker studs together). (Rules 13.10.9, 13.10.15)
• Rule 13.10.13 Lifters: stock diameter only, so no mushroom lifters, and matched to the engine's make and model. Hydraulic lifters must collapse at least 0.1 in. (Rule 13.10.13)

Intake and carburetor

• Rule 13.10.7 Intake: a low-rise cast iron manifold, two- or four-barrel, stock and unaltered, or one of the approved aluminum intakes. (Rule 13.10.7)
• Rule 13.10.7 Approved aluminum intakes for GM: Edelbrock #2101 or #2701, Weiand #7547 or #7547-1. (Rule 13.10.7)
• Rule 13.10.7 For Ford: Edelbrock #2121, #2171 or #2665, Weiand #7515, #8023 or #7516. (Rule 13.10.7)
• Rule 13.10.7 For Chrysler: Edelbrock #2176, Weiand #7545 or #8022. (Rule 13.10.7)
• Rule 13.10.7 No porting, polishing, powder coating or port machining. (Rule 13.10.7)
• Rule 13.10.7 No Bowtie, SVO, W2, marine, Vortec or other special production intakes, and no aftermarket intake that isn't on the approved list. (Rule 13.10.7)
• Rules 13.10.16, 7.3.3 Carburetor. You can run 1 Holley 4150 Series four-barrel, as set out under Carburetor. Carburetors can be protested; the procedure is under Protests (Article 16). (Rules 13.10.16, 7.3.3)

• DST fix Bad reference Official text: Protest Procedures (Article 19) → Fixed: Protest Procedures (Article 16) (Rule 13.10.16)

Compression and size

• Rule 13.10.10 Compression: 10.5:1 at most. (Rule 13.10.10)
• Rule 13.10.11 Displacement: 360 cubic inches at most, or 368 for a Dodge. (Rule 13.10.11)

Rev limiter

• Rule 13.10.17 A rev limiter is required, set to no more than 7,400 rpm. (Rule 13.10.17)
• Rule 13.10.17 Mount it out of the driver's reach from the cockpit, where officials can get to it easily at any time. (Rule 13.10.17)
• Rule 13.10.17 Altering the rev limiter or the ignition in any way to get around this rule, first offense: 30-day suspension and $1,000 fine, plus loss of that night's track and national points. (Rule 13.10.17)
• Rule 13.10.17 Second offense: 1-year suspension and $2,000 fine, plus loss of the season's track and national points. (Rule 13.10.17)

Option 3 is a stock-looking engine with no limit on cubic inches. Engines in this option can be protested; the procedure is under Protests. (Rules 13.11, 13.11.9, 13.11.10)

Block and heads

• Rule 13.11.1 The engine must look stock. Firing order: stock for its make and model, GM to GM and Ford to Ford. No changes beyond what this option's rules allow. (Rule 13.11.1)
• Rule 13.11.2 It has to be an engine that could go in an ordinary passenger car without any changes. (Rule 13.11.2)
• Rule 13.11.1 Aftermarket blocks are allowed. Lightened blocks aren't. (Rule 13.11.1)
• Rule 13.11.6 No aluminum heads or blocks. (Rule 13.11.6)
• Rule 13.11.3 Don't remove or alter the motor mounts on the block, and don't change castings or fittings. (Rule 13.11.3)
• Rule 13.11.4 No machine work on the outside of the engine. (Rule 13.11.4)
• Rule 13.11.8 The starter bolts in the stock location. (Rule 13.11.8)

Cam and valve train

• Rule 13.11.4 No machine work on the front or rear of the camshaft. (Rule 13.11.4)
• Rules 13.11.5, 13.11.12 Roller rocker arms are allowed. Shaft rocker arms aren't. Stud girdles are allowed. (Rules 13.11.5, 13.11.12)
• Rule 13.11.5 The rule says roller cams aren't allowed. It then says roller cams with solid roller lifters aren't allowed and roller cams with hydraulic roller lifters are. (Rule 13.11.5)

• Rule 13.11.5 Hydraulic roller lift: no more than 0.525 in measured at the valve "and/or" 0.350 in measured at the cam, as the rule words it. (Rule 13.11.5)

• Rule 13.11.5 Hydraulic roller valve springs: seat pressure no more than 140 lb and open pressure no more than 390 lb, no tolerance. (Rule 13.11.5)
• Rule 13.11.5 No rev kits. (Rule 13.11.5)
• Rule 13.11.11 Lifters: stock diameter only, so no mushroom lifters, and matched to the engine's make and model. Hydraulic lifters must collapse at least 0.1 in. (Rule 13.11.11)

Intake

• Rule 13.11.7 No Bowtie or high-rise intakes. (Rule 13.11.7)
• Rule 13.11.7 Use a low-rise cast iron manifold, two- or four-barrel, stock and unaltered, or one of the aluminum intakes below, also unaltered: no porting, powder coating or polishing. (Rule 13.11.7)
• Rule 13.11.7 GM: Edelbrock #2101, #2701 or #2716, Weiand #7547 or #7547-1. (Rule 13.11.7)
• Rule 13.11.7 Ford: Edelbrock #2121, #2171 or #2665, Weiand #7515, #8023 or #7516. (Rule 13.11.7)
• Rule 13.11.7 Chrysler: Edelbrock #2176 or Weiand #7545. (Rule 13.11.7)
• Rules 13.11.7, 13.10.7 This list differs from the 360 engine's: Edelbrock #2716 is allowed only here, and Weiand #8022 only on the 360. (Rules 13.11.7, 13.10.7)
• Rule 7.3.4 Carburetor. Any Holley two-barrel, as set out under Carburetor. (Rule 7.3.4)

Every engine runs 1 carburetor, naturally aspirated (no turbocharger or supercharger) and with no fuel injection. Carburetors can be protested, and the procedure is under Protests. (Rules 7.3.1, 7.3.5, 7.3.6, 7.3.11)

Four-barrel: crate and 360 engines

• Rule 7.3.3 The crate engine (13.9) and the 360 engine (13.10) can run 1 Holley 4150 Series four-barrel. HP carburetors (Holley's race series) are allowed. (Rule 7.3.3)

• DST fix Bad reference Official text: Crate Engine (see Rule 10.9) → Fixed: Crate Engine (see Rule 13.9) (Rule 7.3.3)

• Rule 7.3.3 There's no size rule, but it must still work the way Holley designed the 4150 to work, with Holley-type boosters. (Rule 7.3.3)
• Rule 7.3.3 No vacuum secondary carburetors (secondaries opened by engine vacuum instead of by the throttle linkage). (Rule 7.3.3)

Two-barrel: standard engine

• Rule 7.3.4 The standard engine (13.11) must run a Holley two-barrel, any model, with a throttle bore no more than 1.75 in. (Rule 7.3.4)

• DST fix Bad reference Official text: Standard Engine (see Rule 10.11) → Fixed: Standard Engine (see Rule 13.11) (Rule 7.3.4)

• Rule 7.3.4 The boosters stay in, but there's no booster or venturi size rule. (Rule 7.3.4)

Rules for every carburetor

• Rules 7.3.3, 7.3.4 No annular discharge boosters (boosters that spray fuel through a ring of small holes instead of a single nozzle). (Rules 7.3.3, 7.3.4)
• Rules 7.3.6, 7.3.10 No aerosol carburetors and no Predator carburetors. (Rules 7.3.6, 7.3.10)
• Rule 7.3.2 You can run an aftermarket metering block (the block that holds the jets). (Rule 7.3.2)
• Rule 7.3.8 No cool cans (a canister around the fuel line that chills the fuel). (Rule 7.3.8)

Spacer and fuel filter

• Rule 7.3.9 You can run a 1 in adapter plate or spacer, the same thickness front to back and side to side. (Rule 7.3.9)
• Rule 7.3.9 From the bottom of the carburetor to the top of the intake manifold: no more than 1.25 in. (Rule 7.3.9)
• Rule 7.3.7 1 standard fuel filter is allowed, between the fuel cell and the carburetor. (Rule 7.3.7)

Run gasoline from a commercially built fuel cell, set in a steel can in the trunk with a firewall between it and the driver. (Rules 7.1.1, 7.4.1, 7.4.3, 7.4.2, 7.4.4)

Fuel

• Rules 7.1.1, 7.1.3 Automotive or racing gasoline. No additives of any kind and no upper cylinder lubricants. (Rules 7.1.1, 7.1.3)
• Rule 7.1.1 Rule 7.1.1 bans oxygenated fuel but allows ethanol blends up to 85%. (Rule 7.1.1)
• Rule 7.1.2 Rule 7.1.2 bans blending fuel with ethers or other oxygenates, and ethanol is an oxygenate. It also bans aniline or its derivatives and nitro compounds of any kind. (Rule 7.1.2)

• Rule 7.1.2 Fuel must pass a Digitron dielectric meter test. Getting your fuel tested is up to the driver or owner. (Rule 7.1.2)
• Rule 7.1.1 Penalty for illegal fuel: loss of the points, money and awards from that event, and a possible fine. (Rule 7.1.1)

Fuel pump

• Rules 7.2, 13.2 No electric fuel pumps, and no belt-driven ones. (Rules 7.2, 13.2)
• Rule 3.7 Where the fuel pump has to sit with a Chevy motor is under Engine placement in Hood and engine bay. (Rule 3.7)

Fuel cell

• Rule 7.4.1 The cell must be commercially built. No boat tanks and no stock automotive tanks. (Rule 7.4.1)
• Rules 7.4.3, 7.4.2 Put it in a steel container, fastened securely inside the trunk, above the level of the stock trunk floor. The rulebook doesn't say where that level is on a car with no factory trunk floor; Trunk and tail flags it for USRA tech. (Rules 7.4.3, 7.4.2)
• Rule 7.4.2 Straps: at least 2 solid steel straps around the cell, each 1/8 in thick and 2 in wide. (Rule 7.4.2)
• Rule 7.4.5 Every mount is steel and attaches to the frame or the roll cage. No adjustable fuel cell mounts. (Rule 7.4.5)
• Rule 7.4.4 A firewall must sit between the driver and the cell and run from quarter panel to quarter panel (the body sides behind the doors). (Rule 7.4.4)
• Rule 7.4.6 Check valves are required. (Rule 7.4.6)
• Rule 7.4.6 If the filler neck and cap don't make a positive seal, you need a rollover valve, of the ball-type, flapper, spring or filler kind. (Rule 7.4.6)

Fuel lines and filters

• Rule 7.4.7 Any fuel line that passes through the cockpit runs inside metal pipe or metal conduit. (Rule 7.4.7)
• Rules 7.4.7, 7.3.7 No fuel filters in the cockpit. The 1 filter you can run is under Spacer and fuel filter in Carburetor. (Rules 7.4.7, 7.3.7)