If an engine is stuck tight enough that a reasonable amount of solvent soaking and prying won't get it freed up, there's always the nuclear option- - - -Set it up under a floor mount drill press, and use a hole saw about 1/2 inch smaller than the bore size to cut away the ring area of all the pistons. On a 235 with a 3 9/16" bore that would be about 3 3/8 inches. The idea is to cut away the piston crown area just inboard of the rings, and smack the weakened piston with a piece of hardwood and a BFH. The pistons will break away and the crankshaft can be turned. Once the connecting rods are unbolted and the rods and the remnants of the pistons are removed, then you can chip away the rest of the pistons and hone, or more likely rebore the cylinder walls. A really badly rust-pitted hole might have to be sleeved, which is still better than having to scrap a block. I used to buy my competitors' "worn out" race engines for pennies on the dollar, and use them to teach my students how to install sleeves. I would end up with a race-prepared standard bore block, with only the wholesale cost of eight sleeves out of pocket- - - -and the public school system paid me to build racing engines! Some of those kids now run their own shops, and their taxes pay for my retirement! A couple of them have a pretty successful racing team!
Jerry
