KrzyDav The size of the CV shafts is different for sure on the gen1 V6 at/mt. I went thru this a while ago with mine. Its an auto so I ordered new auto shafts for it. Phil swapped in the MT diff from Betsy 2. The MT shafts are bigger at the diff end. The mounting flange for the pass side is larger with a different bolt pattern and the shaft on the driver side is larger diameter and different spline. The pass side flange on the diff could be redrilled though.

Rear axle I only ever had the auto so not sure.

Also I just put a gen2 auto diesel 488 front into the monty. It does bolt in place if you change the brackets over, but that's where it ends. The CV's are longer by a little. The drive shaft is to short due to the auto gen2 diff being physically smaller. But I used the gen1 auto shafts I bought before that didn't fit. Bolted right in.

Eric Wegerich
89 Montero as chopped as can be. Now with 5.29's