I wouldn't think that the size of the flywheel would make any difference at all where making power is concerned as you need a specific size to make the connection to the transmission and starter. Moving to a smaller flywheel would only reduce weight by a few ounces at best I'd think.
Have you done anything to the engine yet to help it breathe better like a cold air intake system or maybe a chip for the PCS?
A forum community dedicated to Ford F150 owners and enthusiasts. Come join the discussion about troubleshooting, performance, tires, wheels, lift kits, modifications, classifieds, maintenance, and more!