There are literally thousands of otherwise untouched blown 5.0 liter mustangs running around with no ill effects. All you have to do is keep the boost to a reasonable level and use good gas. My daily driver Tacoma (also my tow rig) is equipped with the TRD/Eaton supercharger with no other changes. That truck has pulled my Mustang through the Blue Ridges twice and back and forth halfway across the country. Now with 150K on the engine/supercharger combo it still uses no
oil between 5Kmi
oil changes. The point is; to get that “major increase in power” without a loss of drivability then the displacement will have to go up (i.e. new motor) OR he can keep the one that he has and boost it. Anything else (i.e. big cam etc.) would boost the power and kill drivability. Plus the installation of a centrifugal supercharger is a weekend’s work at most, much easier that a rebuild or even a cam swap. Now all that doesn’t mean that Ex is not right in that forged pistons would much better, but I don’t consider it a deal breaker because what ever you do to increase power will increase stress on the pistons, not just supercharging.
Steve