Piston ring indexer?
I had trouble with .028s blowing out at about 11 to 1. EDIT see correction below
The Felpros work, and I have reused mine up to 3 times!
The compression volume difference works out to about 2.5cc. Plug that into your compression calculator. I think it will work out to about .25 point in compression.Perhaps a bit more.
I use the piston skirts too, spanning the gap with a thrust face