I've only owned one 383 commando in a '68 Fury. I took off the 906 heads to have hardened seats/new valves installed, and my pistons stuck out of the block at TDC at least .010, maybe more. I did not measure them, but it was visible by eye.
Because the Machining Broach Units at the factory machining division were
set up to allow for a minimum of {.025"} difference between the Factory advertised
measurements and {true height} 'as they left' the machining plant.
