1971 NASCAR International Stock Car Racing Rule Book NASCAR Grand National Championship Division Section 20-15 -- Suspensions

a. Heavy duty springs may be used if similar to original equipment. Rear spring position may be changed, but both springs must be located either inside or outside of frame rails.

b. Sway bars may be reinforced. Additional sway bars permitted.

c. Front end suspensions must be reinforced for safety. Heavy duty spindles and bearings compulsory.

d. Camber: 4 ° maximum.

e. Wheelbase: AMA specs apply. Standard plus or minus 1/2 inch. Both front A-frames may be moved forward not more than 1 inch from original position. Left and right must agree. Wheelbase must remain the same as manufactured, as referenced by measurements from front door jamb post to front axle. In the case of eligible cars having less than 115" wheelbase, only rear axle assembly can be moved towards rear of frame to conform to minimum 115" wheelbase.

f. Tread, front and rear: AMA specs apply plus or minus not over 1 1/2 inch tolerance on either side to allow for reinforcement of wheels and hubs, measured at center of tire, zero toe-in at spindle height. Steel spacers are permitted to utilize maximum allowable tread width. Spacers must be bolted or welded to brake drum or hub. "A" frames must have a stock appearance. Upper and lower "A" frames may be altered for safety and tire clearance. Lower "A" frames must be the same length and mount in the stock position. Left and right must agree. No offsets permitted.

g. No mechanical or hydraulic device for shifting weight will be permitted inside of driver compartment. No hydraulic weight shifting devices permitted at any time. No weight lowering adjustment permitted on left front wheel during race.

h. Minimum allowable left side ground clearance 5" on cars with unaltered floor pans and/or relocated frame rails measured at the lowest point of the frame rails, 7 1/2" clearance on cars with altered floor pans and relocated frame rails measured from the lowest part of cowl and rocker panel and not mroe than 2" higher on the right side--oil pan, exhaust pipe and flywheel minimum clearance 4". Steering linkage 4" minimum. Cars running at 7 1/2" height must maintain 6" on oil pan and steering linkage, 5" on exhaust. Violation of this rule will subject car to disqualification and/or fine.