Casting number 3955272 was used in 1969 for 396 and 402 blocks in two and four bolt. Horsepower ratings were 325, 350, and 375.

3919840 heads were used on 396 (and 402) as well as 427 between 1965 and 1969. They are closed chamber heads and have small combustion chamber volumes for high compression ratios, with even mildly domed pistons.