[kaisen]

If the MDX needs a new longblock, that's certainly more than a "couple thousand dollar repair"....even sticking a good used motor in there would be all of that.

I'd vote to sell it as-is. Pop it on Craigslist for KBB Private Party "Good", less $2500-3000 for a used motor, and you'll sell it within a couple days.

Donating it will net you (and your "charitable" organization) much, much less

If you have no need for it, there's no sense in fixing it