Ive got a Mahle power pak going into a 30 over LT1. My friend is buiding the motor but all he has built is traditional 350s and has never done file fit rings. The kit says "file fit" I take it this means thay HAVE TO BE "filed to fit" and not that they are ALREADY "filed to fit"? And I hear that 16 thousandths is the correct gap? Thanks anyone

 

Have a machine shop do it, should not cost more than $75.00
You can gap it for non-nitrous or for nitrous which has a bit bigger gapping.

 

Most pistons come with instructions for the correct end gap. File fit rings are too large (the gap is too small) as manufactured. you need to open up the gap to your desired measurement. Each ring (except the oil ring) is individually fitted to the specific cylinder in which it will be installed. It is not hard, just time consuming unless have you one of these, like we do at the shop. It takes maybe an hour with this tool. Quite a bit longer to do by hand.



It is much easier to show someone how to do it than to write it all out. I am sure there is "how-to" somewhere out there.

Rich