If it were just the pins you could just buy a pin kit for it and use it again but since the housing is broken I wouldn't mess with it. I'd just give it to someone who already has one to use for spare parts or see if you can get it warrantied.
It's not legal to put any engine in a vehicle that wasn't offered in that vehicle at some time. So long as it's cleaner running I don't think you'd get harrassed by the emissions and inspections people.
I'm getting away with it because the new engine in my jeep is just a newer version of...
Sweet I'm excited for you. Maybe we'll go riding next winter.
By the way, 3500 miles is low mileage for that year of sled. Also fix that little tear before it becomes a big tear. That's just a little tip.