This thread has a number of wrong ideas.

1. Keith Black hypereutectic pistons require a larger top ring end gap and KB is very helpful in telling you how much, assuming you can read and have a calculator (or do multiplication in your head). NO OTHER hypereutectic pistons have that requirement.

2. Federal-Mogul is huge and there's a real good chance that the hypereutectic pistons in a 5.3 were made by them with the same material they use for aftermarket pistons.

3. Will the piston live is nearly totally dependent on the tune-up. That was said above and I agree.

4. Given the choice between a forged piston and a hypereutectic piston in a power adder application I would always pick forged. Always. Pistons can be machined or custom built to give the compression ratio you desire.

Now one of my own: Even in a boosted application, squish makes the combustion chamber to have a lower octane requirement. So plan your piston around that.

Another: Moly rings are in actuality moly-coated or moly-filled rings. Engineers select the ring material according to the engine requirements, then the moly is added to the outer surface of the ring. The ring material can be cast iron or cast ductile iron or steel, could even be tool steel if that was necessary, as long as what touches the cylinder wall is molybdenum.

Pick the best piston you can afford. It's a bummer when a piston breaks and the wristpin gouges a groove in the cylinder wall.

R.