2.5 to 4.0

[XJMJeep]

I found a great deal on a 91 MJ but has the 2.5 with issues.
What would be involved with the swap other than the obvious?

[4.3LXJ]

You will find this is a lot of work and you will need a donor vehicle. Engine, tranny, transfercase maybe if you cannot match spline count, shifter if you use an auto, radiator and all the stuff with it from an MJ. You will need the brackets from the Wrangler to center the fan on this one too.

[xj4life2]

As Steve says it should be simple but its the worst swap I've ever done. Ffelt like I was redesigning the Jeep from the ground up

[4.3LXJ]

You might as well drop a Chevy v* and trans in instead. Same amount of work and money.

[XJMJeep]

Don't seem like a good deal after all!
I've done swaps in the passed but they were mostly Ford to Ford swaps like the 1.6 to the 2.3 easy, the 300 to the 302 easy and the easiest one of all the Chevy 305 to 350 so I gotta say I'm surprised, staying within the brand its so different.
I'm glad I asked, thanks guys!