[kcjones]

Originally Posted by 69gumby

OK back to the 350, the 302 has a huge mid range power loss but WOW they kick butt when ya get em going. I need that mid range power to tow my boat to tahoe. I sure would like to get a 302 into an old Camero someday. I am sure my wife wouldn't mind another car around the house.

What size combustion chamber do I want? Do I want a smaller number 64cc or larger like 74cc?

Depends on the pistons you use. Using a stock type flat/valve relief type piston, a 64cc chamber is gonna put you around 9.5:1, whereas a 76cc is gonna give you 8.2:1 or so. But if you use domed pistons, you can use the 76cc for that 9-10:1 ratio or the 64cc for anywhere from 10-12:1. Obviously, fuel grade, outside temp/air density, altitude, other engine components will limit how much compression you can run safely.

Most performance small blocks running on 91/92 octane are safe with 9.0:1 with iron heads, 9.8:1 or so with aluminum, given temp/alititude are average. I'd go with flat pistons and 64cc aluminums, big valves, middle size runners (220?). Although the vortecs are smaller runners, they flow better than most at lower lift, giving you great torque numbers low in the rpm range. If you're going iron on pump gas, plan carefully. Nothing like getting an engine together, and hear that ping...and then turning the timing WAY back to get it to stop and losing all your power.