My machinist measures the pistons. There is a wear limit by the factory. If the pistons are not too worn we re-use them. I think I have only replaced them once and then It may have been with less worn used pistons.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.