Hello Ralph, My rings should be better than original factory because when I make them I heattreat rings with lower tension. This is because my rings are round and I don't need to put a lot of tension to seat ring because it is round. Factory rings have more tension to seat ring, but also wears them out sooner and heats engine more. Where I'm going is with less tension larger port not much of a problem as long as rings are pinned so ring gap doesn't go into open port window. Remember less tension, less heat & ring lasts longer with less chance of over heating. At present time I have rings for Stihl: 028 44CC, 25.4 CC, Super 045, 57CC, MS 440. Great engines with lots of power. Hope that answers question. Hope you got my Piston Ring List Bill, if not email me again as computer returned some of you emails. Thanks Frank