I have never used a metal piston stop. The service manual never called for one. The 070 manual my buddy provide is the lastest and it gives you the part number to use and it's the same to the Huztl link. This saw is big fellas. Did I say big? Huge. That's a 14mm plug hole so around half inch rope in that cavern of a cylinder. Anyway I bought one to use for those reasons. If I shoot myself I will admit it.