Engine Cylinder HeadThe Edelbrock #60759 Performer cylinder head is designed for 302, 327, 350 and 400 cid small block Chevy engines up to 1986. This cylinder head includes your choice of 64cc (In order to retain stock compression ratio on 1970 and earlier small blocks) or 70cc combustion chambers and high flow intake and exhaust ports. A Complete head includes larger than stock 1. 46" valve springs to handle most high lift cams. This head retains the stock intake port