magnum heads, 10.6 to 1 and a mild cam?

I'd toss that 262 in the car without a second thought. I have a solid 11:1 and a Crane with roughly the same specs. I run on 85 octane all day long. Of course being up here at 5000 feet helps. Take in to consideration that furnace you live in will offset the altitude as far as air density.