Originally Posted by jnicewan
Easiest by far and cheapest option would be to replace the 4.0L
This option is a direct drop in. While I'm all for v-8's and more power, there are alot of things that pop up during the swap that can raise the cost in a hurry. Plus all the aspects you don't think about until you are breaking axles at every turn. More power means weak points are more easily exposed. Plus cost of adapters and or swapping the trans/t-case, radiator, etc. You didn't say what type of wheeling you do so I don't know if you are looking for more power or if you were happy with the 4.0 engine.
If you are planning on going bigger with axles, wheels tires and all that down the road anyway then go for the v-8. If you were happy with the 6 cylinder and don't want the headache of re-engineering your entire drive train, then drop another one in and call it a day.