Best Budget Build Motor

I'd rather have the stroke over the 318 - so my vote is take the 360, sell the heads from it, sell the 318 Magnum you have complete, buy a set of EQ Magnums rather than wasting time on the factory heads, and either have the cam reground, or replace it with something better. The 360/300hp crates used the stock Magnum camshaft from what I've seen. It shouldn't take much to get a little more steam from a regrind or larger with the better heads.