6.9 piston ring suggestions

[Frstdiesel]

Ok guys, need suggestions for piston rings.
1984 6.9 with 90k miles.
Doing a refresh on it. Bores are great, no taper, original crosshatch marks still there, no ring ridge, std bore.
Planning to have the machine shop do a light hone while the block is in for vatting and align honing.
Questions I have:
1. recommendations for ring set and vendor (Mahle pistons, original rings are 5/64")
2. File fit or not
3. Suggestions on 2nd ring (Gapless or file fit)
4. End gap size for top and second if file fit.
5. Proper break-in/seating of rings.
Thanks a million.(miles)
PS this has an old Banks Turbo set-up. Going to be used for occasional towing up to about 8k lbs, not a daily driver.
Probably be less than 15 psi boost.

 

[Thewespaul]

Mahle or sealed power have served me well. File them if they need adjusting to be in spec, if they work out of the box run them. For the second ring it’s up to you, I do gapless on my performance builds but it’s not a necessity. For gap just run the factory spec, spec sheet should come with your rings. Break in is also up to you, for engines I build I ask my customers to do lots of stop and go city driving for 100 miles and avoid heavy throttle, after that break it in like you will be driving it.