Why would one need to swap axels? As far as I know My 4.0 YJ uses the same axels as a 91 2.5, Dana30 front and Dana 35 rear. The 2.5 should have a lower gear ratio in the axels enabling one to run larger tires with no problem. Depending on the year the transmision might be an issue. the peugot tranny is junk. An ax4 or 5 should be alright. The cost would vary a lot depending on the cost of the 4.0 with acessories and your ability to do the work yourself or not. I would guess 1000 to 2000 dollars. <img src="/forums/images/graemlins/cheers.gif" alt="" />