Thanks for all the input, yes, I want to use the 915 heads because I have some money into them and Im not looking to spend more on aluminum heads. my option may be to put the .060 gasket on it, mix it with some Sunoco purple, and figure out what octane booster works and keep some in the trunk in case I get stuck getting gas somewhere without the ability to mix my fuel. and yes, the heads were cc'd, that's how I know they are 75cc chambers. I was hoping with the 484 cam with 68 degrees overlap it would kill some of the cylinder pressure.

Duane