# Piston and rings question



## Dave76 (May 3, 2016)

Hi guys,
I'm a new member and I need some help.
I have an old belt driven McMillan air compressor that needs a new piston and rings kit. What part of the piston do I need to measure before purchasing one? Obviously diameter but none on eBay give the height of the piston. Too tall a piston will do damage and too short will lack good comp, true? Confused!!!


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