[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

[65 Lamnas]

Originally Posted by bhieb

Hi 65 Lamnas,

This is great info on the timing chain cover! So, If I did upgrade to a 11 bolt timing chain cover and used an early 69 water pump, would I be able to retain my existing crank pulley and 65 style power steering and alternator mounting bracket?

Brad

If you did all that, I'm not sure how you would verify your ignition timing. The 68-later cars used a different timing tab than the 67-earlier cars. The damper (balancer) was changed in '68 and was a different diameter. I'm not saying it could or couldn't be done, just have not done that type of a swap myself, and that would be the only headache. Your pulleys and brackets (belt-alignment) would not be an issue with the early-'69 11 bolt pump.