Pistons are Scat forged that I picked up a few weeks ago.Seems to me like the cost to use the cast 4 inch crank would exceeded the value you will get back. I personally can’t see going to that expense and using cast pistons for a 450 hp goal. Seems like you already have a 408 that is built the way you want at the power level you want. Just my two cents worth.
Goal is not 450 … that is just a guess . My goal is torque and smooth power . Since I have to address the bearing issue which probably includes a line hone etc why not spend another grand and do it right while its out ? It should be a kick with the 46rh and 3.55s