The easy way is to loosen the head bolts a couple of turns, pour about half a cup of oil into each cylinder, put the spark plugs back in, and tap the starter. Basically, a field-expedient hydraulic jack. If the engine is in running shape, just loosen the head bolts and start the engine. That's how we loosened up flathead Ford heads rusted tight to 24 studs. Sometimes we had to drive 'em around the block!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!