In the 1960s and 1970s, Chevrolet and Pontiac both offered a pushrod V8 engine with an advertised displacement of 400 cubic inches. Considering that both carmakers are (were?) sub-brands of parent ...

How much can I mill down a 6X-4 head? I'm building a stock 455 that's 0.030-over with flat-top pistons and an "068" cam. I'm trying to get my compression up, but still run on pump gas. The engine is ...

The 1967 Pontiac GTO gave buyers a rare choice between two distinct 400 cubic inch performance paths, the 400 HO and the Ram Air package. Each engine delivered serious speed, but they did it with ...