Street-Stock (Pure Stock) Class Rules
1. Engine must have stock cast iron block, heads and exhaust manifolds, Only (Stock, O.M.E. intake manifold, Cast Iron or
Aluminum. No stroker, no de-stroker, 370 CID.
2. Hydraulic flat tappet cams and stock lifters. (No anti pump ups, no Rhodes lifters or mushroom type.)
3. No roller cams allowed. Maximum of .470 lift at intake and exhaust valve.
4. Front engine, rear wheel drive mandatory.
5. Maximum compression ratio 9.3:1
6. Combustion chamber volume must be at least 72 cubic centimeters. Maximum 1.94 intake valves.
7. No porting or bowl work allowed. Flattop pistons only.
8. One (2-v) two-barrel unaltered carburetor, O.E.M. type, 500-c.f.m. Flow maximum. Non-original carburetor for manufacturer is allowed; 4412 Holley carburetors optional. 1 inch spacer/adapter maximum.
9. No Four-barrel carburetors.
10. Optional tubular nonadjustable upper control arms are allowed.
11. All cars subject to inspection at any time, and may require the removal of all illegal components.
B. Transmission and driveline
1. Factory transmissions only.
2. Factory torque converter must be functional.
3. May change rear axle ratio, but must not be higher numerically than 4.11:1.
4. Rear suspension must remain unchanged from stock.
5. Open rear ends only. No limited slip. No shimming allowed.
C. Body and suspension
1. Front hoop is allowed for safety.
2. Minimum 107.5 in. wheelbase.
3. Steel-bodied cars only; no convertibles, t-tops, or sunroofs allowed.
4. Entire body must remain factory stock appearance and materials; no after-market fenders, hoods, doors, bumpers, clips, etc. allowed. After-market nose is allowed
5. Doors may be skinned to allow fitting roll cage
6. Front inner fenders may be removed if not required by suspension.
7. Uni -body cars may use sub frame connector to tie front and rear suspensions.
8. Suspension, steering, and brakes must be original equipment.
9. Replacement parts made to O.E.M. specifications are allowed.
10. Alignment changes are allowed as long as components are not modified.
11. No updates, backdates, options, etc. are allowed; the car must appear mechanically and cosmetically as it did coming out of the factory.
12. Fender openings may be trimmed for tire clearance.
13. Car weight with driver minimum 3,200 pounds. No ballast permitted.
D. Tires and wheels
1. DOT radials only; must be passenger-car types.
2. No retreads or bias-ply tires. Tread must remain original; no grooving, sipping, or snow tires are allowed. Tread width measured across top of tire must not exceed 8-inches.
3. Tread-wear rating must be plainly visible on the outside of the tire, and must be greater than 250, also subject to minimum durometer reading.
4. Tires must not protrude beyond body.
5. White spoke-type steel wheels or reinforced-center stock steel wheels are permitted.
6. Brakes must be functional on all four wheels and no after-market proportioning valve
7. All four wheels must be of the same size.xt.