Installed but never run with moly rings. My engine builder picked them and I would rather just go with stock cast. The engine is still assembled, so if anybody is interested I will have to get it pulled down. Asking $250 plus shipping. May consider selling with the resized rods (stock bolts) on them.
These are the H 392 NP, about 9.5:1 with 69cc heads and composite gaskets. So pretty close to the original 70's, as they were not even close to the 10:1 they rated them at for the 455 and 10.25:1 for the Stage 1. That's like the 71-later were rated at 8.5:1 and they were about 8.2:1.
I noticed they cut 4 reliefs in the piston, so if they only cut 2 it might be the right compression or better. Does the forged 70 dish seal power have more compression than those? I ran a set with 2 reliefs cut deep to where the just made a slot behind the ring and they lasted 10 yrs and might use them again. Everyone says you will burn those up and I never did. Im wondering if mine with those deep reliefs where less comp than the ones you got?
These h392np's have a 1.985" compression height w/23cc dish. The 1970 stock 455 and early forged replacement had a 1.975" compression height and an approx 22cc dish. So you lose 1cc but gain approx .11 in static comp. overall due to the .010" higher compression height.
