1968 NASCAR International Stock Car Racing Rule Book NASCAR Grand National Championship Circuit Section 20-33 -- Safety Belts

a. A quick release belt no less than three inches wide is compulsory. Shoulder harness and additional V-type seat belt compulsory.

b. Both ends must be fastened to frame of car with aircraft quality bolts, not less than 3/8 inch in diameter.

c. A steel plate may be welded to frame on right side of driver so the belt can be brought down in such a manner that it will keep driver from sliding from side to side under the belt.

d. The belt must come from behind driver.