This is what "kroil" was meant for. Tke the Kroil five day challenge-fill the cylinder to the top with kroil on the morning of day one, top up on the morning of day two, repeat on day 3 , etc. let it soak, let it soak, let it soak. on day 5, have at it with a 1 pound hammer and a chunk of hardwood. If it doesn't break free within 15 mintues of pounding, step up to a 2 or 3 lb hammer. watch your fingers. If at this point it still doesn't want to break loose, Capt len is on the mark- time to pull the engine, bolt it to a stand and turn the engine over on the engine stand, drop the pan and check the crank case. If the crank isn't a corroded lump of crud, there's hope. Unbolt the connecting rod, and try to send the piston north instead of south.