Ok, I see.. well, maybe 450" cam is to big then if my heads aren't going to allow me much compression.... sounds like to much money to blow on 273 small valve heads anyways... I've got some 915 J heads that are in good shape but those also will kill my compression on a stock 318... like in the 7s.... wow. It's all a Hot Mess! Lol.... just want something like 9.5 CR without big problems or bunches of cash on aftermarket heads... sounds like 8 1/4 CR will be a struggle.... but it is what it is....