Filing the ends of file-fit piston rings makes the rings in the bores egg-shaped. Install standard gap rings.
In 1969, the previous owner bored the 350 CI block .030” os in my 1962 Chevrolet Bel Air. He installed new forged Sealed Power flat top pistons with .0035” skirt clearance for 10.3:1 CR. He used GM rings and standard bearings in the 1968 350 CI engine. He installed a GM 3863151 (RPO L-79) camshaft. The engine had about 20K miles on it and came out of a wrecked 1968 Chevrolet C10 pick up.
The previous and original owner told me the GM rings were the same as the standard gaps and standard tension, Sealed Power rings. Those rings are 5/64” plasma-moly top, 5/64” iron second and 3/16” stainless steel oil rings. When I purchased the car two years ago, the engine had 50k miles on it.
Last edited by MouseFink; 06-14-2019 at 11:48 AM.