from what ive seen in a few magazines the 4.0L does not bolt into the 4 cyl. space. new mounts and such will need to be made. so, it may be easier to find a 4.0L TJ or if the swap is what you want then maybe look at the costs of a V8. preferably a full drivetrain swap from a truck of other suv. it may come down to whos doing the swap, if you're paying soemone then it wont be cheap anyway you do it.