Eagle

Those are XJ shackles, based on the instructions. Look at photos of stock MJ rear shackles, and don't go by what some aftermarket company suggests about installing on a different vehicle. Although, according to the facory manuals, the orientation should be the same for the XJ and the MJ -- and it would have the flat with the decal facing rearward, not forward.

http://comancheclub.com/topic/48372-a-little-rear-shackle-info/ FWIW, those JKS shackles are installed facing the wrong way.

43 divided by 14 = 3.07. That's your axle ratio. On the shackles, what's the distance between the upper and lower bolts, center-to-center?

Why do you need a double Cardan joint with a SYE? Double Cardans are used when the operating angle exceeds what a single u-joint can handle. It's necessary on the front because the drive shaft is so short. It's not necessary on the rear unless you've got a very tall lift -- and even then I doubt it's necessary with a long-bed MJ.

Not really. A LOT of AutoZone parts have a lifetime warranty. They just play the odds and figure you won't have the vehicle by the time you need to warranty the part.

That's a handy little tool. Thanks for posting the link.

You didn't know that the XJ has a shorter wheelbase than even the short-bed MJ? Of course the XJ drive shaft is too short.

Did the transmission and transfer case (and the "new" driveshaft) by any chance come from an XJ rather than an MJ?

I don't understand the question. Everyone who has done this swap has done one or the other. The Jeep 2.8L flywheel has a huge, eccentric weight on the flywheel. The 3.4L engines are internally balanced so they don't need that weight on the flywheel. If you bolt on an unmodified 2.8L flywheel, the engine will start and run but it'll shake and vibrate enough to make you think it's going to fall apart within five minutes. I haven't played with the 2.8L / 3.4L swap, but I encountered the same problem when I bought an AMC AMX that was originally a 390 and some previous owner had dropped a 343 into it.

^^^ This. Letting the coolant sit idle in the heater core all summer is what promotes clogging. There's a reason why Jeep eliminated that valve in the newer XJs.

Servimos los tacos sólo en los viernes.

https://youtu.be/UO3CaJieLK8?t=7

MJ rear speakers are either 4x6, or 4" round mounted on an oblong plate. Good luck fitting 6x9s unless you want to chop the cab framework.

Clogged heater core.

Looks nice, but no oil pressure or temperature gauges?

The Comanche front combination valve has NO proportioning function in it. All proportioning is taken care of by the rear, height-sensing valve. That should be readjusted if converting to disc brakes. Putting an actual proportioning valve in the front will only reduce the braking force to the rear, and it has no provision for the bypass line so if you change the front combination valve to a proportioning valve, you have to abandon the height sensing proportioning valve.

So give us a hint. What was the problem, and how did you fix it?

Sort of. When I bought my '88 Chief it had a lift on it. The rear lift was a pair of long AALs. The ride was horrible. After driving it and wheeling it for a couple of years I finally realized that I not only didn't like the lift, I also didn't need it. So I put a pair of stock XJ spring in the front and pulled the AALs out of the rear. I needed rear shocks at that point and didn't have anything that would fit, so I bought a set of Pep Boys cheapest Gabriels, and the ride was MUCH better. That bottom, straight leaf in the factory spring package is an overload leaf. It doesn't do anything when you're running light. When a load drops the three primary leaves enough to contact the overload leaf, it stiffens up the suspension to carry the load.

I think you have the wrong wire connected to the hot side of the high beam indicator. Why would you connect it to the turn signal? It's on with the high beam HEADlight, so tap the hot side off a headlight.

No real advice, other than to tear it down and find out what broke. It sounds like you blew a piston.

What's "proper"? The ZJ V8 was a Mopar 318, which was an old, heavy engine. Of course, the XJ/MJ 4.0L in-line six is an old, heavy engine. The ZJ V8 springs are the same as the XJ Up Country springs in a 4.0L, and they ride 1-inch higher than stock in a 4.0L XJ (or MJ). I'm not up on SBC specs but I doubt the 350 would/could weigh significantly more than the Mopar 318 or the Jeep 4.0L, and it might weigh less. I would expect between 1 and 2 inches of lift -- but that's purely a guess.

About 15 years ago I paid $500 for a pristine short bed box, complete with tailgate and taillights. I also had to make a 200 mile round trip to pick it up. I would expect a nice one to be worth a lot more today.

Dana 35. The springs appear to have a non-OEM helper leaf of some kind. The metric ton package always came with the dana 44 rear axle.

That's why I wrote that you will need to adjust it after the conversion.

It won't match up. The tops of the '97+ fenders transition from vertical to horizontal with a smooth radius. The early fenders have a chamfered transition. If you use the early style header with the late-model fenders, you'll need to use some bondo to modify the chamfered corners of the header to a rounder shape that will match the fenders.