Eagle

Optional -- at least in 1988.

Technically, the 2.8L V6 wasn't a GM engine, because AMC actually paid money to GM and bought the rights to the POS. They weren't buying GM engines from GM. Talk about dumb decisions. The 2.8L didn't produce significantly more power or torque than the I4. Apparently, shortly before the Cherokee was introduced in 1984, the thinkers at AMC decided that they needed to offer a V6 engine as an option, and GM was only too happy to sell them the old 2.8L, since GM had given up on it at that time. For GM, it was a win-win -- they unloaded an albatross, and got paid for it.

^^^ This

Well, I'm the second most stubborn person in the world. When I bought my '88 Cherokee Pioneer new, I paid extra to get the operable vent windows. They leaked. I went back to the dealer, who brought in the Chrysler area tech rep. His solution was to offer to replace the operable vent windows with the fixed glass triangles. Refund the money I had paid to get operable windows? Oh, heck no. So I kept my operable vents and tried to stop the leaks. The problem is at the end of the metal track on the bottom of the glass. It makes a sharp step, and the rubber gasket can't properly seal at that junction, so that's where the window always "weeps." The only thing that worked for me was to liberally apply a coating of silicone grease, and then close the vent. The problem is that you have to keep reapplying the grease if you open the window(s). My XJ has (had) air conditioning, so I have kept the vents sealed shut for twenty five years, and they don't leak. But they are there if I ever need to use them.

Rustproofing is good, but what most places sell as "rustproofing" is nothing but undercoating, and that's bad. It doesn't bond well to the steel, it allows water to get between the metal and the coating layer, and thus promotes rust rather than protect against it.

If buying a replacement stock-style bumper, before installing it throw several coats of paint or a coat of bedliner on the back. Consider clear-coating the exposed face, or be prepared to wax it frequently. The ones you get today are vastly inferior to the originals. Several years ago I replaced the factory rear bumper on my '88 XJ. It had lasted 20+ years in an environment of heavy winter salt use, but it was shot. Got a new (NEW, not used) bumper from the Jeep dealer. It lasted three winters, and within that time it rusted out worse than the one it replaced. I have an '89 parts XJ with 219,000 miles on the clock that has a much better rear bumper, and an almost perfect front bumper (the front will go on an '88 MJ 4-banger). Be sure to seal up any new OEM-style bumper to keep moisture from getting into and behind the (alleged) chrome plating.

Either one will require either changing your wiring harness, or giving up the "HO" configuration of the "new" engine and setting it up to run with your existing RENIX wiring. If you're up to the wiring swap with the engine, I would choose the '96 because that's the first year for OBD-2, allowing you to use a common OBD-2 scanner. The '91 requires either a proprietary scan tool, or reading the fault codes by flipping the ignition key and counting the number of times the light blinks.

I have no idea from this what you did, but it doesn't sound right.

The front parking brake cable is (or was not long ago) available from Auto Zone. Not sure what you mean by "release latch."

I'm not assuming anything. The facts I cited are facts, irrespective of the OP's intentions. The owner's intentions don't change the fact that the Ford 8.8 is narrower than a factory Jeep axle. You say narrower tires can be run on the 8.8 with factory rims. I disagree. Maybe that would work if the tires are smaller than 225/75-15, but I doubt it. And the owner's intentions don't change the fact that a stock Jeep drive shaft u-joint doesn't mate up to the stock 8.8 pinion yoke. Certainly the owner's intentions are important. IF the owner plans to run aftermarket rims with significantly less backspacing, the narrower axle width may not be a problem. But -- in that case running the same rims on the front will almost certainly require cutting the sheet metal. Some people don't mind doing that -- others prefer not to. It's a factor that has to be considered, and when people just say there's "no problem" using the 8.8 without pointing out the things that might increase the cost and effort of using it, IMHO that's not complete advice and THAT's when assumptions are being made. That kind of advice, without pointing out the potential added costs, is assuming that the advisee's priorities are the same as yours. The 8.8 is a decent, strong axle. Some of them come with disk brakes and a LSD. For someone who is already planning on running wheels with less setback and is prepared to accept the other expenses that would increase the cost over that of using a Chrysler 8-1/4 axle, fine -- the 8.8 can be a good choice. I just don't think it's fair to point a person asking for advice in that direction without pointing out the other factors involved.

Not helpful. Fact: The Ford 8.8 axle is narrower than XJ/MJ axles. With a factory axle, 31x10.50s on factory 15x7 rims just barely clear the inner fenders, and the inner sidewalls rub the body whenever the rear axle gets a little twisted relative to the chassis. Changing to an 8.8 requires either using wheel spacers or aftermarket rims with significantly less backspacing. Fact: A Chrysler 8-1/4 axle uses the same u-joint setup at the pinion yoke as the factory MJ D35 -- no adaptation needed. You cannot just bolt the factory drive shaft to a Ford 8.8 axle. What part of that is not correct?

Well maybe you should clarify your statements instead of giving partially false information. What information have I given that's even partially false incorrect?

Maybe this will help. On the right track, where the diagram shows the number 2 pointing, there's a piece that looks like the one on the driver's side but it doesn't have the lever welded to it. That's where the wire goes.

If the axles are original to the vehicle, the 4.0L 5-speeds ALL came with 3.07 gears. And that's a good part of the reason why you're not feeling a lot of power. IMHO that gear ratio should never have been used. It keeps the engine WAAAAAY under the torque peak at highway speeds. 5th gear is useful only for maintaing speed at highway speeds. Under 55 MPH 5th gear is useless, and for passing you still need fourth gear on the highway (unless you're out west where they have 70 MPH speed limits. Let's put it in perspective. The torque peak of the '88 4.0L engine was at 2,400 RPM. With 30" tires, at 65 MPH in 5th gear the engine is turning at 1760 RPM. If you downshift to 4th gear at 65 MPH, then you get near the torque peak -- 2345 RPM. I don't think your engine is as bad as you think it is. It's just handicapped by the axle gearing.

You mean, like ... stock (factory) Jeep wheels? Not everyone wants to run aftermarket rims. If you do, that's another expense on top of the cost of the axle if you go with a Ford 8.8. There's also the cost of a pinion yoke adaptation. If the cost of the axles is about the same, there's no question that the Cherokee 8-1/4" is the easiest, least expensive way to go. I'm not saying the 8.8 isn't a good axle, I'm just pointing out that with the 8.8 there will be costs beyond the price of the axle and the relocation of the perches.

You mentioned 30-inch tires, but what engine, what transmission, and what axle gears do you have?

Mate, remember -- the newest MJ was built 23 years ago. We don't throw anything away. If you don't need it, somebody else will.

And ___?

On the other hand, a Chrysler 8-1/4 out of a Cherokee will be the correct width, whereas a Ford 8.8 will require running spacers on the rear axle. The cost of a decent set of spacers (billet aluminum, not cast) adds a significant amount to the price of an 8.8 axle.

Not the answer you're looking for, but have you considered dumping the TBI? If you have to replace that injector, it's scary expensive compared to the individual injectors for the 4.0L and later 2.5L engines. And it's not an especially efficient form of injection anyway. I've been toying with the idea of just scrapping the TBI setup and reverting to a 2-barrel carburetor (or maybe even a very small 4-barrel, but for an I-4 that's probably overkill). It shouldn't be too difficult to find or make an adapter to mount a 2-barrel on the TBI intake manifold. You would also have to use a new fuel pump, because a carburetor only needs about 7 psi. The TBI pump puts out enough pressure that it would defeat the float and needle valve in a carburetor.

Don't toss the extra parts, pass them along to a brother here at Comanche Club. Somebody must be looking for them.

What code is it throwing?

What size tire is that? When I was running on 31x10.50-15s I had a 31x10.50 spare under my SWB with no mods needed.

I've never heard of a third seat for an MJ and I've never heard of a part called a seat bezel. What are you asking about?

With 225,000 miles on the engine, it doesn't owe you anything. I wouldn't put a lot of money into a full, professional valve job on a high-mileage engine without doing the rings and bearings at the same time -- in other words, a full rebuild. IMHO you're a perfect candidate for a quick-n-dirty valve job in the driveway. If it works, you can drive it for another 50,000 or 75,000 miles. If it doesn't work, you're not out a lot of money.