1974 NASCAR International Stock Car Racing Rule Book Limited Sportsman and Hobby Divisions Section 20D-29 -- Tires

a. Any NASCAR-approved tire allowed provided it does not exceed maximum side wall measurement of 12.70 inches plus .15 tolerance at 60-pound pressure, mounted on a 9 1/2 inch rim. Measurement must be made with new tire. No knobs or worn out tires allowed. No cross grooving allowed. No smooth tires permitted at start of any event.

b. Recaps allowed on 1/2 mile or shorter tracks.

c. Width of any recap tread cannot exceed width of original new tread for that tire and the maximum tread width is 11 inches. When retread tires are used, all four tires must be same width and tread design.