The TJ transmissions are different in many ways, clocking of the t-case, shifter tower, t-case shifter linkage style, trans mount, etc. The XJ one is a direct fit. That being said, I have a 99 TJ AX-15 in my 88. Go to picturetrail.com/petermontie and look in the drivetrain folder.
Jeep on1
--Pete