400hp 318

if you are going with a stock piston the 80's 318's have a small chamber which is more compression. just add 1.88 1.60 valves and some porting you will be good to go. i ran 14.77 with those heads stock with the stock cam. you should be fine, andi run 87 and have no ping

if you use the kb piston you can use a 360 head.

steve