[bhieb]

Originally Posted by Goatracer1

I use stock replacement forged pistons. I got the drop in compression from the chamber work on the cylinder heads. The #62 heads already had bigger chambers than the 421 heads. The engine had just under 9.6 to 1 compression. Years later I used those very same heads on my wife's 1962 389 to temporarily be able to run the car on 89 octane while I built a new engine. The engine would not run even on 93 octane with the 389's original heads.

Hi Goatracer1,

I'm really glad to hear that enlarging the chambers on the #62 cylinder heads is a viable way to drop compression ratio. This might be the easiest way to get my engine to run on pump gas. Can you provide some more details about the cylinder head work you had done?

Brad