[bill37341]

CSX 3183- I thought they were the same, too. The 63, 64 & 65 pistons used a 5/64, 3/32,3/16 ring pack & the C8-S used a 1/16, 1/8 pack. I sleeved my early '65 motor for these '63 pistons , had everything balanced & discovered the difference. I find that NOBODY carries a 3/32 ring, & decided to use my C8 pistons (of which I only have 7 good ones). Thanks for your response anyway. Bill.