The G heads are the highest compression heads currently available. The compression ratio depends on the displacement of the engine they sit on top of. The actual compression is probably not more than 9:1 on a stock 312.


Lawrenceville, GA

Just picked up a complete engine, block number is ECZ-C and heads have ECZ-G. In looking at charts they say compression could be 8.6. 9.0, 9.1 or 9.7. All show the same cc. How do I tell which? I haven't taken engine apart yet. Don't need a lot of parts sitting around since it is a future project.

Ol'ford nutCentral Iowa

56 Vic w/292 & 4 spd.