I just got done with a 4x4 conversion. You can't just bolt the t case to the 2wd trans. However you can swap the shaft out of the 4wd trans(it will probably bolt on fine but the shaft isn't long enough to reach the internals in the t case) and the tail housing then the t case will bolt on. In my case I swapped the whole trans cuz the 4wd one I had was rebuilt. Be sure to swap the crossmember out to. The t case will hit the floor board and vibrate like crazy.
I'd be glad to help with any questions you have. Feel free to pm and ill help the best I can.