Stock Car Rules | Boyd Raceway

Boyd Raceway Stock Cars Rules For 2025

1. FRAME / BODY: Any American made stock passenger car body on a stock unaltered full frame. No Camaros or Pontiac, Firebirds or Novas. All cars must have original wheelbase with 108” minimum with no more than 1” difference from side to side. NO Front wheel drives. Stock appearing aftermarket plastic nose or tail pieces are allowed. Rear of car must be sealed off, no exposed fuel cell. 5” Maximum spoiler allowed. Bodies must be centered over wheel wells (front to rear and side to side). Body panels may be replaced with steel or aluminum but must resemble OEM appearance and body lines. Must maintain OEM appearing Roof Pillars. Front visor is allowed on the windshield area MAX 7 inches. Rear of car must be sealed off from trunk lid/deck to top of frame rails, fender to fender. Sunroofs and T-tops must be reinforced and enclosed. All glass, plastic, upholstery, lights, mirrors, and trim must be removed. No part of dash can be more than 28” from back edge of the center of the hood. Entire trunk floor may be removed. Rear frame horns may be replaced. Must us 2” X 3” tubing no further forward than back of shock tower. ALL openings should be covered as to isolate the driver, subject to track approval. Racecar body should be maintained in such a manner as to keep a presentable appearance.

2. BUMPERS/RUB RAILS: Maximum one inch wide by two-inch-tall steel or Lexan rub rails allowed – bolted flush to body. All front bumpers must be mounted minimum six inches from front frame horns. Steel bumper mounts only. No sharp edges allowed on bumpers, rub rails or bolts. One of three bumper options must be used and must be OEM height: OEM: Front Bumpers not covered by plastic nose piece must be complete, unaltered OEM, capped to fender with steel, welded or bolted. If constructing front bumpers out of tubing it cannot extend past frame horns. Rear bumpers not covered by plastic tail piece may be unaltered OEM capped to fender with steel, welded or bolted. No bars past outside edge of body other than rub rails. Aftermarket: Fabricated tubular bumpers allowed, but must be covered by plastic nose or tailpiece and bent to fit with rounded ends. Front bumper bar must be minimum 1.5-inch O.D. (maximum two inch) with 0.083-inch (maximum 0.125 inch) wall thickness. Rear bumper must be minimum 1.75-inch O.D. with 0.120-inch wall thickness.

3. ROLL CAGE / SAFETY: Minimum six-point cage, minimum size 1-1/2” O.D. by .095” wall thickness. minimum three horizontal bars in driver’s side door, and three horizontal bars on passenger side door. Five-point quick release seat belt and harness required for driver. Aluminum racing seat only, must be bolted in using minimum .375-inch bolts. Seat must remain inside all confines of roll cage. Must have window net and full fire suit including shoes, gloves, neck brace and SA2005 or newer helmet for driver. (if driver elects to utilize a Hans type device, driver must have a full containment seat with left and right head braces) Must have three bars in front of driver in windshield area. Must have door plate on driver side. Door plate should be 18-gauge metal from rear of roll cage to five inches in front of the seat from top door bar to bottom door bar.

4. DRIVER COMPARTMENT: Driver must be sealed off from track, driveline, engine and fuel cell. Kick and rocker panels may be removed. Front OEM firewall may be replaced using steel fabricated firewall, 18 gauge or minimum 0.049-inch thickness. Dash must not extend more than 28 inches back from top of firewall. Dash must be flat, rear can be no higher than front, except for cowl in front of driver. OEM floor pan may be replaced using steel fabricated floor pan, 18 gauge or minimum 0.049-inch thickness, securely welded to frame. Floor pan may be replaced from front firewall to rear halo supports. Must remain flat/OEM appearing from frame rail to frame rail or within cockpit, can be no higher or lower than frame rail. Exception is maximum eight-inch-tall driveshaft tunnel. Tunnel must remain similar to OEM tunnel in size. Cockpits are allowed; interior may be enclosed. Inner panel on outside of passenger door bars allowed. Rear firewall may be aluminum or steel and may be located no further forward than rear halo supports and no higher than bottom of rear opera windows. All holes in firewalls must be covered with metal. No driver-adjustable devices allowed while car is in competition except brake adjuster. No mirrors.

5. ENGINE: All engines used in competition must be able to be used in production U.S. passenger cars without alteration. Nothing over 362 Cubic Inch and no 400 parts allowed. Solid motor mounts allowed. Maximum engine setback #1 sparkplug no further back than center of upper ball joint. All coolers must be located inside the engine compartment. No coolers allowed in the driver’s compartment. Must run 500 CFM Holley 4412 2-barrel only. Must be unaltered. Carburetor may be modified to Holley HP Dorton part no. 0-80583-1

6. CYLINDER HEADS: OEM production 23-degree steel cylinder heads or aftermarket 23-degree steel cylinder heads only. No aluminum heads. Screw in studs, guide plates and stud girdles allowed. 3/8 or 7/16 studs 2 allowed.

7. LS Engine Option: 4.8, 5.3 or 6.0 GM LS with OEM pistons, rods and crankshaft. Standard bore blocks only, no boring cylinders, iron blocks only. Heads must be stock OEM, no porting or polishing. Untouched cylinder head. Aftermarket valve springs okay. Must run 500 CFM Holley 4412 2-barrel only. Must be unaltered. Carburetor may be modified to Holley HP Dorton part no. 0-80583-1. One electric fuel pump allowed. Must run a fuel pressure safety switch. Carburetor must pass go-no gauges. Must run MSD 6014CT Circle Track GM LS engine ignition control. No other engine ignition control allowed. Rev limiter must be set at 7000 RPM. All cars with an LS motor are required to run a fuel pressure safety switch.

8. 602 GM Crate Engine Option:
a. Must be unaltered sealed GM 602 crate engine. Upon Inspection, any different, altered or
missing GM seals bolts will result in disqualification.
b. GM 602 sealed Crate motor may utilize any Holley four-barrel carburetor, all components (float
bowls and main body) must be Holley Manufactured. Metering blocks and base plate may be
billet aluminum non-Holley. No aerosol-style carburetors allowed.

9. EXHAUST: Headers optional 609, 930, 935 mufflers.

10. INTAKE MANIFOLD: Any catalog mass produced aluminum intakes are okay. No porting or polishing.

11. TRANSMISSIONS: Any stock type automatic or manual. Must have one working forward and one reverse gear. Direct drives are allowed with coupler. Trans. Cooler ok, cannot be mounted in driver’s compartment. Manual transmissions may use single or multi disc clutches, flywheel and pressure plate must be steel. Mini clutches are allowed. 2” minimum Steel drive shafts must be painted white and have a loop 6” from front u-joint. Automatics must have an approved scatter shield constructed of minimum .125 X 3” steel, 270 degrees around flex plate. Shield may be welded or bolted to the floor board inside the car. Manual transmissions must have an explosion-proof bellhousing. Bert, Brenn, Falcon transmissions are allowed.

12. FUEL: Pump or racing gas only. NO additives or smells. Fuel cells must be secured in trunk with a minimum
of 2-inch strap all the way around the cell. Flapper valve or twist lock air craft style cap required.

13. FRONT SUSPENSION: All components and mounts must be steel, unaltered OEM in OEM location GM to
GM and Ford to Ford. Rubber, nylon or steel lower A-frame bushings only – no offset or bearing type. No sway bars. Exceptions are weight jacks allowed – must be in original centerline of spring tower: OEM upper A- frame mount may be moved or replaced with aftermarket steel non- adjustable mount.: OEM or OEM replacement ball joints allowed. GM mid-size metric frame- OEM upper A-Frame may be replaced using aftermarket upper A-frame or Hemi Joint Style A-frame (must be steel A-Frame). Lower A-Frame may be tubular aftermarket but mount in original OEM locations. Shock location may be moved and may go through center of aftermarket upper A-frame, frame may have 3” opening cut for shock clearance. Single hole shock mounts only. Tie rods, center link and adjusting sleeves may be aftermarket. NO suspension stops of any kind allowed.

14. REAR SUSPENSION: All components and mounts must be steel, unaltered OEM or OEM replacement, in OEM location and match frame. No independent rear suspension. OEM rubber or nylon control arm bushings only, no offset or bearing type. Welded single hole shock mounts only. Exceptions are: coil springs may be moved – front to back, centerline of axle tube can be no further forward than the front of the spring, or no further back than rear of spring, but spring must remain vertical left to right: shocks may be moved, but must remain behind rear end housing on metric frame cars: rear end lower control arm mounts maximum 7.5 inches long, may have maximum five holes for adjustment. Lower spring perch must be welded to axle tube. Solid safety chains securely mounted from upper frame rails directly to axle tubes allowed (cannot be mounted to any floating device, must have slack during inspection). After market trailing arms allowed as long as they match OEM length center to center of bushings and bushing diameter. Weight jacks, rear sliders or lowering blocks are allowed. No torque arms allowed.

15. REAR END: Any steel approved OEM passenger car or truck non-cambered rear end (housing and carrier) allowed. Safety hubs (floater) allowed. No sway/pan hard bars. All components must be steel, exceptions are: lowering blocks, and u-joint caps, and drive flange may be aluminum. One inch inspection hole in housing required. Full steel spool, steel minispool or welded rear end only. Steel axles only.

16. SHOCKS / SPRINGS: One steel nonadjustable unaltered shock per wheel. All shocks must completely collapse at any time. No external or internal bumpers or stops. No coil over or remote reservoir shocks. No coil over eliminators. One spring per wheel only. Minimum 4.5 inches O.D., maximum 20 inches in free height, non-progressive coil springs only.

17. STEERING / DRIVER SEAT: No rack and pinion. All components and mounts must be steel, unaltered OEM, in OEM location and match frame. Exceptions are: bolt on spindle savers allowed, OEM steering column may be replaced with steel knuckles and steel steering shafts. Quick release required – steering quickening and steering wheel may be aluminum. Steering boxes must remain in stock location. The driver seat may be no further back than 25” forward of center line of rear end housing measured at the base of the seat.

18. RADIATOR: Any (1) radiator that fits in original location without any body modifications is allowed. Water pump mounted fans only. NO electric fans. Fan spacers ok.

19. IGNITION: One 12-volt battery only. Must be mounted securely in rear of driver’s compartment or trunk area. Battery in driver’s compartment must be enclosed. One distributor in stock location only. May run point or HEI style distributors. May run aftermarket MSD style distributor and box. Plugs and wires may be aftermarket. Ignition on/off switch must be clearly marked. NO traction control devices of any kind.

20. BRAKES: May use stock type master cylinder and brake components or aftermarket racing master cylinders. Must have at least 3 working brakes. Right front may be blocked. Brake bias adjustment allowed. Disc brakes allowed. No aluminum or composite rotors. Must use stock type steel rotors front and rear.

21. TIRES AND WHEELS: 8” maximum wide wheels allowed, 15” diameter steel wheels only, wheel covers and mud plugs right side only. Bead lock allowed on right side only. NO bleed-off valves. Must run 1” steel lug nuts. G-60 Tires only. Tire must durometer 45 or higher after race. Grinding, sipping and grooving allowed.

22. WEIGHT: Weight may be securely added in trunk or under the hood, but not in plain view or within the driver’s compartment. Weight must be painted white with car number on it. Car must weight minimum 2950 lbs. With driver after race. Loss of bolt on weight during competition will be an automatic disqualification