You can also use a big hole saw to cut the top of the piston(s) out just inboard of the rings- - - -about a 3 1/4" diameter or so, driven by a variable speed 1/2" drill motor. Use a floor mount drill press if you have one available, and support the block on a stack of boards at the oil pan rails. The pistons are trash anyway, since the rusty cylinders will need to be bored (or maybe sleeved). Once the ring area is freed up the rest of the piston can be driven out easily. 235 pistons in various oversizes are all over Ebay- - - -and the same ones that fit the full pressure engines have the exact dimensions as the spray oilers.
Jerry
