To Russ's point, I don't know if correct height 1968/69 hp 383 pistons were ever available.
I've never taken apart an original 68/69 hp 383....... Did those motors actually have positive deck height pistons as delivered from the factory?
No they never did , that was the NHRA spec to allow them to get compression with the 906 head.
A stock 68/69 383 piston is .002/3 in the hole on a spec deck height, at best they were 9.2:1 when new.
The Speed pro 2315 is the tallest 383 piston at 1.920 , it's an NHRA replacement piston so it doesn't have a valve relief and weighs a ton. The next tallest is the Diamond piston at 1.916 and has valve reliefs at 5cc I believe , I'd use that piston , tweak the CH and have them put in smaller valve reliefs at zero deck ... which is what I did on the one Dan screwed together for me.
KB pistons are 1.908 , both of them, and have huge valve canyon reliefs at 6cc. The only piston that is a bigger waste of money than KB is a cast rebuilder piston that is made for all years of the 383 and is way down in the hole.
