Skip the rebuild lol! That's actually reasonable for the remanufactured one. Save the woes and have it swapped jmho.
I went to the salvage yard and picked up a used t-case for my jeep xj but then thought hey I'll rebuild my damaged one at same time...
I spent a ton of time doing rebuild and new everything internally but was kinda bone headed. The j y t-case is still going stong.
Albeit, I now have a very nice rebuilt t-case.

 

I still do think you should at the very least verify what happened to your current engine. Maybe oil filter popped and engine can be saved.