Well, if the engine is locked up that damn tight, just bust the pistons with a hammer and a chizel and remove the crank and rods...You are gonna have to bore it anyway..I once hadda 440 that was locked up so tight, we hot tanked it COMPLETE THREE times and nothing...Finally ended up busting the pistons out of it...BE CAREFUL though, as it's WAY easy to go right through a cylinder doing this on a stuck motor...