Long story short, I bought a 2wd trans and need a 4wd trans. The output shaft will obviously not fit into the t-case. I misunderstood and thought you could use the transmissions interchangeably by swapping the rear section of the housings . Is there any other option to making it work other than getting a 4wd trans??

Tried to have a driveshaft built and make the truck 2wd temporarily but the driveshaft would have to be too long for anyone to safely build, and I don't want to get into fabbing a crossmember for a 2-piece shaft.
Also, I doubt I can return the trans b/c it came from a private seller on the other side of the U.S.A.

 

The internal parts will interchange, but you will need the output shaft and tail housing from the 4X4 unit. I recommend you call 1-702-873-4534 and either make a deal for an exchange or order the book, rent the tools, and swap the parts from the two units you have. It will take an average mechanic about 6 hours to do the conversion if both units are clean.

My first recommendation is to exchange for the correct rebuilt unit, as the syncro rings and bearings are very weak and most used transmissions will require an $850 rebuild kit just to get them up to snuff.