Just thought Id mention the magnum head as another cheap way to bump comp. It's runners are inbetween the 360 and 318 ports so it matches up nicely for a power build 318 head. You can expect around 400 hp with stock pistons and a .480 ish cam without port work.
There are fans of the 302 head who claim it can make more power than the magnum on a 318. Might be true might not be,but you will have to do a TON of porting.
Magnum main disadvantage is that you need a magnum intake or drill your heads to accept la intakes. It needs magnum specific head bolts as well. Needs oil thru pushrods and lifers but not a big deal there. Most aftermarket cams already have oil thru lifters as the amc lifter is the same as the sb mopar but has oiling hole for rockers,so companies just make one lifter for both brands.
