No, there are a different number of bolts, different size, and 7 main bearing instead of 4 on the 250. You're opening up a huge can of worms if you try to go to the later model engine- - - -nothing will fit. The bell housing bolt pattern is different, and so are the motor mounts. Where are the cracks you're concerned about?
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!