perplexing situation

[Andy]

A good website that will help you is, http://www.empirenet.com/pkelley2/DynamicCR.html You need to figure out what your dynamic compression ratio is. Download his calculator, and enter in your engine's specs. According to Kelley, long as it is around 7.5-8.5:1, you should be fine on pump gas. If your dynamic compression is over 8.5:1, then you'll need to run a higher octane fuel than 93. The more overlap your cam has, the more compression it will bleed off. I've been researching this stuff for a few years now, since I'm putting together a pretty serious 406 for my 67. The combo I plan to run will have a static compression ratio of 9.8:1 and a dynamic compression ratio of 8:1, which will be perfect for 93 octane pump gas. My engine builder said that anything over 8.25:1 dynamic would create problems with detonation in the summer, and I would have to pull timing out of it. My motor should put out around 520-540 hp and around 550 ft lbs.