I imagine this would be easy to do?
What about the rear hubs, would they be needed also???
Would the standard prop length fit onto the 2wd diff
was this aimed at my suggestion of using 2wd? If so then literally the whole 2wd saph (not 3dr the arb locations are different) beam goes in place of the 4x4 one....only thing to change over is the brakes as 4x4 are vented and 2wd are solid (they bolt straight on).
prop will fit.
2wd and 4x4 rear hubs are same
Cheers,
Dan.
P.S. you can also fit a 2wd diff into the 4x4 rear beam by removing 1/2 inch
(EDIT 1/4 inch NOT 1/2 inch 
) from each side of top lugs (plz check before cutting on my advice). Not sure if you need shafts (thinking not). that way you only have to buy a diff....and shafts max...prob the most cost effective way if you have