piston to head clearance
i recently freshened my 383 chevy up. its got a internally balanced forged crank, 6.0 eagle rods, and je pistons. its a 12.1 vortec headed motor. i shift @ 5700 and go through the traps @ 6300. i`m now running depending on which piston and where you measure it in the hole ( on the top or bottom of the block deck) with head gasket installed from.030 to .042 . the motor had 200 runs on it and bearings were really not even broken in yet...my point being there wasnt alot of odd movement on the bottom end . crosshatch was still real clear in cylinders. soo , .030 is a calculated risk of what level?