1989 2.5 and 4.0 same bellhousing???

I have a 2.5 and am looking at putting a 4.0 in. Do I have to change the bellhousing? Is there anything else I need to know? Help. I know the wiring will have to be changed. Thanks for info.

Simon

See http://www.naxja.org/forum/showthread.php?t=31554 - post#13

That helps but is the tranny I have an AW4 or is it different?

The 2.5L used a Chrysler 904 automatic tranny. AW4 was only with the 4.0L.

To do the swap, you will have to completely swap the wiring harness including the one under the dash unless you want to spend a ton of time patching. You will need to swap the fuel pump, tranny, engine mounts. Don't know about a 2.5L in an 89, but in an earlier XJ, the whole front sheetmetal is different between the 2.5L and the 4.0L. You may get by with just the radiator support since yours is an 89. I did a 2.5L to 4.7L stroker swap on an 85XJ. Sure is fun to drive, but you would be time and money ahead to find a 4.0L rig and buy it, then sell your 2.5L.

In an atempt to redeem myself for the stupid bellhousing inncident I just went out in the driveway and compared 87 2.5 and 91 4.0 and sheetmetal is definetly cmpatible just rank the 2.5 rad mounting bracekt and toss it and the 4.0 rad should drop in. I suspect only model years which didn't have the 4.0 option would need major changes there. Also check to see if your newer 2.5 will actually require a fuel pump swap. I realize of course that earlier carbeurated 2.5's will need a swap, but does it apply to fuel injected models as well?

I've been told that the TBI version on the XJ used around 13psi whereas the 4.0L uses 39psi on the early models and 49 on the later models.