I'm rebuilding a vortec 5.7 to swap into my truck and a guy at work has a set of dart iron eagle heads with a 64cc Combustion Chamber. They're cheap, my heads are questionable and his are almost perfect, would they be worth buying to stick on? Only other mods I would be doing to the engine is a cam, tune and headers. The new engine is bored .040 over (357ci) if that matters.