1974 NASCAR International Stock Car Racing Rule Book NASCAR Grand National ® Championship Division Section 20-19 -- Bodies

Original dimensions of all bodies must remain as manufactured, except for changes which may be necessary for tire clearance. No lowering of body or frame. In the interest of safety and handling characteristics, a non-adjustable spoiler not exceeding 3 inches in height may be attached to rear deck lid. An approved spoiler may be mounted to the front underside of cars. The optional non-adjustable front spoiler must be installed a minimum of 3" behind the lower trailing edge of the front bumper and the leading edge of the spoiler cannot extend forward beyond the lower trailing edge of the bumper and cannot extend over 2" below the lowest point of frontal area. Spoiler cannot extend beyond center line of front frame rails. Spoilers must have a minimum ground clearance of 4". All support brackets must be mounted to rear of spoiler--only metal spoilers permitted. All spoilers must be approved by NASCAR before installation.

a. An approved spoiler must be a solid non-adjustable part of the body which controls the flow of air over one surface only.

b. An airfoil must be a permanent part of the automobile body which allows the passage of free air over the top and bottom surfaces of the horizontal plane of the airfoil structure. (ACCUS).

When airfoils are approved on the basis of ACCUS eligibility recognition forms, the approved airfoil must fit the NASCAR body templates and can only be adjusted within the manufacturer's limits as recorded on the ACCUS eligibility forms. Airfoil adjustments and control are not permitted to be made from the driver's compartment.

c. All cars must have complete bodies, hoods, fenders and bumpers and grilles in top quality condition. No aluminum, light alloys or fiberglass will be permitted as substitutes for steel for any parts of the bodies or bumpers. No homemade grilles permitted. Aluminum and fiberglass trim parts may be approved as replacement parts for die cast parts, but must be approved by the NASCAR Technical Director.

d. Cars must be neat appearing. Head lining and door trim pads must be removed and top panel must be painted. Inside door panel and quarter panels must remain standard, except for approved alterations for roll bar installation. Doors and inner quarter panels must be covered with aluminum. Inner panels cannot exceed a maximum of 3 inches in width and must angle a minimum of 1/2 inch down toward the inside.

e. Floors must be complete and in standard position except for tire inspection; no funnels or air ducts. Engine fire wall must remain standard. Spare tire well may be removed but hole must be covered with metal and welded.

f. Windshields and rear glass must be installed in their original standard positions and standard windshield and rear glass molding must be used and also installed in standard position. Chrome trim or molding must be bolted or pop-riveted in a safe and workmanlike manner. Windshield Safety Clips 3" x 1" x 1/8" must be installed. Three clips bolted to top of car and extending over edge of windshield. Two clips will be bolted to the cowl and extend over bottom edge of windshield. Bottom clips must be visible. Clips must be spaced a minimum of 12" apart. Rear window must be secured with 2 steel straps not less than 1/8" x 1" bolted to roof panel with 5/16" bolts.

g. All doors must be fastened in an approved manner. Steel straps 1/8" x 3" must be welded from the body to the roll bars. Two straps to be welded on front side at hinge locations. Two straps to be welded on the rear side of the door (one) top and (one) bottom. Steel strap 1/8" x 3" must then be welded to the doors so as to match with the previously welded straps and straps bolted with 3/8" bolts. Door handles must be removed and the holes covered with a piece of aluminum only. Doors must be removable.

h. No streamlining allowed, such as headlights, radiator grilles, top of windshields or under pans. Cars must remain standard in appearance. Grilles may be closed to width of radiator, but must be done on the backside of the grille. Grille must be stock standard height and width and mounted in stock location. When ducting air from the grille to the radiator a removable panel or door eight inches by 12 inches must be in the top of the duct forward of the radiator for inspection of the backside of the grille and radiator. Grilles may be covered with two layers of unpainted screen wire attached to grille only. Closed grilles for qualifying or racing will not be permitted.

i. Fenders may not be cut or altered except for wheel or tire clearance which must be approved by NASCAR technical inspector. When cutting fenders or quarter panels for tire clearance the original tire opening contours must be followed. (See diagrams on the rear pages of rule book.) Note for AeroWarriors.com users - there are two diagrams: here and here.

j. Hoods must remain in original locked position and closed. Hoods must have original springs and hinges so as to hold up hood when open. All hoods must be locked with 4 evenly spaced pins in hood with attaching cables.

k. Rear deck lids must have operating original type hinges. Deck lids must be equipped with a self-holding device so as to keep lid up when open. Deck lids must be fastened with 2 pins--one on each side. Deck lids must be standard, no cutting of reinforcement permitted.

l. Any car which fails to fit NASCAR templates or meet body specifications may be required to carry penalty spoiler or smaller carburetor restrictor plate.