318 head???

Ported 318 heads milled for compresion of at least 9.5-1 (Unless you allready have a high compresion slug within) and stainless steel Ferra racing valves, 1.88/1.60 (360 valves) port matched to the intake. This will give a max velocity intake charge. Or the same for the 273 heads. There smaller chamber is a plus in the compresion deptment.

On the cheap, MP HD Hyd. rockers are OE rockers, but new. There ratio isn't all that, so, if need be a must to have the lift, Ya might as well go with something like a Hugesengines or Comp cams roller rocker set up and custom length Pushrods on a chrome hardened shaft with bitchin billet hold downs. But thats money.