Grant Piston Rings part # P1449.000 work great in R100 engines, so far. I put them in my GS and so far, so good. I couldn't find the Fed Mogul rings. I'm told they're discontinued.
They're going into the RT next.
I've been shot, cut, burned, blown up, fired, busted, promoted, reprimanded and decorated. What are you going to do? Ban me?
Blessed be the Lord my God, who prepares my hands for war and my fingers for battle. Psalm 144:1