440 Source Head Opinions?

...... But isn't the whole point of the 440 source ??? .... a way to replace the worn out factory cast for approx the same cost as rebuilding the factory cast... ???? with a 50 lbs lighter set of heads, and even in a mild case if you only gain 15 ft lbs of torque and 15 hp, it's still more of everything that's 50 lbs lighter for the same cost as putting new guides, springs, maybe exhaust valves, grinding the seats, resurfacing, and valve seals all in the old cast ??? I mean, either way, it's up to the builder. But I fully understand the reason folks would just buy a new set of Stealths