Budget cylinder heads for a 318

Just do yourself a favor and ignore the 318 haters....and there ARE a few even though they say they aren't. I mean heck, if you end up with a 340 or 360, great. Just don't let them talk you into discounting a 318, because they can be made to haul the mail. Somehow, I believe you already know that.
@Dan the man
This is 100% true.
I’ll not argue that a bigger engine will do it better and easier, but there is nothing wrong with the smaller displacement engines. It just takes a little more. For your description of your target, the 318 is not going to have a problem.

Build what ya got and have fun.