302 heads

I wouldn't get to stressed out about compression of course it's gonna run better with more cr but it's all about compromises, 318 are low to mid 8's:1 but as long you don't want to go to crazy with cam, your cam choice is probably on the edge of what will work acceptably with a stock long block. But if 302's fit with your future plans for your car then go for it but if not I'd spend the money on gears or something else.