Reply to "TRW L2416F Piston Compression Height?"

Indexing the ring gaps at 120 degrees assumes that the rings all rotate at the same rate so you index them at the start and none of the gaps can ever align to allow blow-by.
This is not true- some rings rotate faster, some in the opposite direction to the others and a few do not rotate at all. We all do this but it likely makes zero difference since in a properly built engine running at its design temp, the ring gaps are minimal and end-gap blow-by is insignificant. Very large gaps, or too tight end- gaps will cause big problems but you can't go wrong following the ring mfgrs specs.