Just an update, going with a internal balancing forged scat 496 rotating assembly with H beams and probe supercharger low compression pistons. Custom cam, retro hydraulic roller lifters, Rollmaster billet timing set, Romac Neutral Balancer and Flywheel, cometic Head Gaskets for marine blower engine, and a melling oil pump. I was told this combo should put me around 600-650 (reliable) hp on pump gas.

I did find out that the oil pump pickup tube was in the pan when I took it off. I had good oil pressure, but can't be sure what it said when engine started knocking and then seized up. Hmmmm... also, some of the bearings on the rods had lost their lock mechanisms and spun, but other wise (beside the blown piston) it didn't look that bad inside.