1965 NASCAR International Rule Book Specifications NASCAR Grand National Championship Circuit Section 20-8 -- Engine

a. No 1963-1964-1965 hemi, high riser or overhead cam engine or head allowed. No 1963 Chevrolet high performance 427 cubic inch engine allowed. (See Rule c-2).

b. Numerals indicating the cubic inch displacement of engine must be painted on both sides of hood in numerals at least eight inches high.

c. Internal polishing, porting, altering and/or relieving of motor parts permitted as specified by NASCAR.

d. Oversized oil pans and oil coolers are not to be used unless approved by NASCAR. Oil pans must have a minimum ground clearance of five inches.