They look great. Have you tried SeaFoam for carbon removal. It worked pretty good on my cylinder heads for the heavy carbon. Where are you sourcing the rings? Are you looking for 52 108 01? Thanks Greg
We are getting rings from iSaveTractors.com. Our mix in the ultrasonic tank is some amazing parts cleaner that works wonders for carbon. We also ran the engine for about 10 hours before the teardown with a pretty heavy dose of Marvel Mystery Oil in the fuel, which helped a little on that top ring groove. Haven't used Seafoam directly on the carbon before. Will give it a try 👌🏼