I have a 2004 f150 5.4ltr four wheel drive with a bad transmission. I have a donor truck that is a 2004 f150 5.4ltr 2 wheel drive. The transmission code on the door jamb stickers both say B. Will the two wheel drive transmission work in my four-wheel drive truck just by swapping out the transfer case?

 

Nope, different tailshafts and tailshaft housings.

 

You can swap the output shafts and the extension housing. You have to completely tear down the transmission, install the 4x4 output shaft, and rebuild the trans.

 

As Mark said, that's going to be intensive to do as a DIY'er if you don't have prior knowledge of automatic transmissions. Let alone the tools.