Don't scrap the old engine. Even with a cracked block, lots of usable parts will still be there- - - -crankshaft, connecting rods, cylinder head, sheet metal, rocker arms, pushrods, and a lot of other bits and pieces. Some cracked blocks can also be repaired, especially if the crack is in the water jacket, to the outside of 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!