Pro-Stock Class Rules (see also General rules)
A. Engine
1. Engine must be same make as body. Example: GM to GM, Ford to Ford, Chrysler to Chrysler.
2. Forward-most spark plug shall be no further back than a line connecting upper front ball-joints.
3. All heads and blocks; must be made of cast iron. No aluminum allowed. Flat tappet cams only, no rollers.
4.Tubular steel and cross-over headers are allowed, but exhaust must exit behind driver, under the car and safely. “Zoomie” and 180° headers are not allowed.
5. Single-plane intake manifolds are allowed.
6. Engines must us solid engine mounts. Accessories can be changed. Mid-plates optional.
7. Electronic ignitions are allowed.
8. Carburetor with Maximum 800 cfm. are allowed. Exotic carburetors including, but not limited to Dominators, Predators, etc. are not allowed; fuel injection is not allowed. No alcohol fuel.
9. No dry-sump oiling systems.
10. Minor radiator protection is allowed, and must be made of same material used for roll cage.
11. All cars are subject to inspection at any time and the inspection may require the removal of illegal components.
12. Radiator must be in front of engine.
B. Transmissions
1. No competition transmissions are allowed.
2. O.E.M.-type single-disk clutches only; no Ram-type couplers are allowed.
3. All automatic transmissions must retain functional torque converter.
4. No aluminum flywheels are allowed.
C. Body and Suspension
1. Minimum allowable wheelbase is 107-inches.
2. Minimum car weight is 3,000 pounds (with driver, after main event).
3. Steel and aluminum after-market bodies, fibergalss roof are allowed. Body must replicate O.E.M. body shape.
Plastic nose and tail clips allowed. No fiberglass bodies.
4. No wedge-style bodies are allowed.
5. Spoilers are allowed, with maximum height of 6-inches; no wings or side-plates.
6. Frame or sub-frame must match body type (e.g. GM-to-GM, Ford-to-Ford, etc, except that pickup truck bodies can use a passenger car chassis.
7. Driver must sit within 1-foot of original position, and cannot be sitting atop driveline.
8. Front suspension must match frame and be complete. If subframe connector is used in mid-body area to connect front and rear subframes, complete stock front must still be used.
9. Uni-body vehicles may have tubular frame from front sub frame to rear of vehicle. 3rd links, coil and leaf springs are acceptable.
10. Suspension must be O.E.M., but attachment points may be modified and heim joints are allowed in steering, panhard bars, and shock absorbers to include 3rd link’s
11. Stock 4 links only (Examples: Monte Carlo, Olds Cutlass, etc.)
12. Suspension mounting points may be changed as long as factory components are not modified.
13. Spindles, rotors, and calipers must be O.E.M. and of the same make as the frame.
14. Racing shock absorbers can be used and mounts moved, but coil-over shock absorbers are not allowed.
15. Suspension bushings must be O.E.M. size.
16. Lower control arms must be O.E.M. for the front suspension used; tubular upper members allowed.
Non adjustable.
17. Rear axles may be full-floater, but no cambered axles allowed. Ford 9-inch rear axles allowed in any vehicle.
18. No cambered axles, quick-change rear gears, or aluminum or other lightweight axle housings.
19. Steering quickener are allowed.
D. Tires and Wheels
1. Approved track tire is any racing re-treaded carcass, with a minimum 66-hardness compound. No Hoosier Dirt Boss allowed. Note: Sources will be made known before the season starts, but this tire is required for the class.
2. Grooving and siping are allowed; bleeder valves are allowed.
3. Any racing-type steel wheel allowed, but bead-locks are allowed on right rear wheel only.
4. No spacers with a thickness greater than 1-inch are allowed.
5. Wheel stud threads must protrude from lug nuts.
