Cast pistons are fine for STOCK (330 HP) motors, Hypereuctectics will work fine in a stock engine too. Anything much over that and the time bomb is ticking. Over rpm from unintended flying, or any detonation will lead to gravel sized chunks of piston in the pan. We repair/rebuild at least 6-8 jet-boat engines a year with shattered hypers in them. Anything over an aftermarket intake/carb deal or cam or headers and you are on borrowed time. Spend the $$$$ on forged pistons, and do it at a machineshop that specializes in boat motors. Car engine parts and clearances aren't the same. Call during business Hrs. for details. TIMINATOR 623-877-8553