If I'm starting with a bare block or a shortblock,and having to get heads,big port heads that is,then I'm going to,in most cases spend at least 1500 dollars,and more likely closer to 2 grand for a set of 690 or 583 CORES.Then I've got to spend more money on things like valve guides,valves,springs,seals and the necessary machine work.This can exceed the price of the Eddies or Wallas,and the alloy heads are 65 lbs lighter than that old stuff.Unless you got a basicly complete longblock to start with,are building a " numbers correct" engine for a show type vehicle,or just "have to have" the factory castings for personal reasons,the aftermarket heads make much more sense to me.