HO swap into 88 Renix

[foreman1063]

I have a 88 Pioneer Big Ton, 4x4 manual, with 230k miles. The motor is decent but I'd like to update with a HO version. The donor is a 94 Cherokee, auto, with 83K miles. My plan is to replace the entire drive train, wiring harness, ECM, etc.

By replacing the entire harness(dash forward) will I run into compatibility problems, or problems in general? I have the FSM's for each truck so I will be able to slowly get through the swap but I'd like to get any insight from people who have done this before.

[Geonovast]

Since you have an entire donor vehicle, and already plan on swapping EVERYTHING, you should be good. You're going to need an MJ fuel pump sending unit in order for your gas gauge to work properly, however. You'll also obviously need a new rear driveshaft...

 

You're going to run into an issue with axles. Swapping the front shouldn't be an issue, but you'd have to lose your D44 rear to use the XJ rear. You will not be happy with an auto and those 3.07 axles.

[foreman1063]

Drive shaft modification, good point. I was thinking I would swap in the XJ gauge cluster too, so I guess I will need to use the donor pump/sending unit. I should have been more clear, I'm swapping everything but the rear 44. I have a low mileage,44 Trac-lok and 3:73's from a TJ I'll be putting in the rear and putting the regeared, XJ non disco 30 in the front.

[Geonovast]

It's not an option of whether or not you use the 94 gauge cluster, you have to. ALL wiring, engine bay and dash, has to be swapped. You'll need to splice your taillight wiring into the XJ harness... I'm sure there's a write-up how to do that somewhere, since XJ and MJ tails do not work the same.

 

XJ pump and sending unit will not work in an MJ gas tank. You need a 91-92 MJ sending unit... which are not easy to find.