Question on 302 heads for a 318

I think what Rumble said in regard to valve sizes is good. For everything else but valve springs, stock is fine. For springs, I'd run something like Comp Cams 901-16s. They will work with more aggressive cams if you feel the need to cam up later. Also, you may want to have them milled. The '60s 318s had slightly smaller chambers than the 302s typically came with.