i'm no expert by any means, but should be a longer rod motor so should make more torque.
you could probably go with cast unless you're planning on making a good chunk of power, all depends on your budget and preference.
deck size is a little different
302 - 8.2 vs. 351w which is either 9.2 or 9.5 to it'd be more of a height issue than anything else.
just my .02