1974 NASCAR International Stock Car Racing Rule Book Late Model Sportsman Division Section 20B-20 -- Rear Axles

a. Rear ends may be interchanged in any manufacturer's line.

b. Locked differentials permitted.

c. Quick change center section optional.

d. Heavy duty rears recommended.

e. Full floating rear axles compulsory.

f. 3/4 ton rears may be used.

g. Differential oil coolers, approved by NASCAR, permitted.