390 vs 408

Haha not going to happen soon ;D When summer comes though! Anyone who can give me some hints on what stock heads to use, I have a set of pre-magnum 360 on the 318 now, how well will they do if ported? How 'bout a crank? Which one? I'm not one who uses top of the line stuff when it's not needed so I want something that will hold up to about 500 horses but hey, no reason for it to be built for 1000... What pistons? I'm going forged, just to be on the safe side, you can never spend to much on pistons, I learned that the hard way. Help, help help =D You are great! Thanks for all the answers, just amazing!