The stock 383 bore is the same as the 426 bores, 4.250. Boring it .065 will make it 4.315, why do that I've built a bunch of RB and 426 Hemi at either 4.310 or 4.320 bore sizes when needed, never thought of trying to find or have 4.315 pistons made and use 4.320 rings on them, why are you wanting to do this?
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
