1974CJ5

Starting to look more and more like this can't be done with leaving as much of the xj stuff un modified as I would like. Not pulling the plug yet, but my hand is firmly on the cord.

Dang my phone got carried away... sorry mods.

The second image didnt load for me before. I think I'm aiming between the two... i would like to incorporate the bed from the mj, but not change the wheel base... the wheel base in the red one is definately been altered... but the red ones look is closer to what I'm after... thanks alot for the links they arre a great visual reference...

Holy crap! Looks pretty darn close... do you have a thread!?!

I know this has been brought up before, and I have looked over those threads, both successes and failures, but I want to do it a little different. I want to take a cherokee (2000 model) and basically cut it off right around the center of the rear axle. (I do not wish to change the wheel base of the xj) And take a lwb comanche and cut it over the center of the rear axle and use from that portion back. From my preliminary evaluation it looks like the "frame rails" (I know its unibody and the rails will have to be fabbed) will line up reasonably well. If I play my cards right I shouldn't have to disturb the current spring hangers. I imagine I will be using the back section of the mj's cab to seal off the xj's cab. I plan to either shorten the bed and have it separate or weld it directly to the rear of the xj for a more solid look. Thoughts? From what I can tell I will not have to change the position of the current fuel tank in the xj. I shouldn't have to greatly modify the e brake. Other than the rather substantial sheet metal fabrication job ahead, and moving the sound bar over the rear seats, and extending the tail light wiring,figuring out how to make the flares, and modifying the trailer hitch to work on the mj's rear end... Am I overlooking anything obvious? (I will have to get creative in retaining the 3rd brake light also.) From my preliminary calculations looks like it should extend the rear of the xj about 22 inches approximately. So I should end up with around a 4ft truck bed. (Also I would be using a totaled mj so I would not be massacring a perfectly good mj for the project. :) )

Well folks thanks for all the help. I was only considering this swap because I already had the parts and at first glance didn't seem like that much of a ordeal, and I was willing to deal with an under powered auto 4x4 mj, just for the perceived cheapness, and the increase in functionality. Since it is going to cost much more than I had hoped, I think I will begin trying to source a chevy 350, sm465, np241 for the mj. I appreciate that you would offer me 500 for the xj, but the interior is so super clean, and the vehicle so low mileage I think I could beat that price by parting it out or simply by fixing it, by quite a bit, and I know that means a lot of work, but I am not afraid of a lot of work. So thank you anyway.

So assuming I get this flex plate and all is good, how hard it is going to be to make the hole for the cps. I tried to see if my 904 had the cut out, but I can't get back there to see for all the :mad: vacuum lines. I am 99.9% sure it doesn't. If my memory serves the cps cutout is only about a half inch wide, and 1.5 to 2 inches long, but getting the positioning right scares me... The AX5 is sounding better all the time... :wall: Especially since I think if I use an ax5 I can just source a drive shaft from a junked that has the ax5/np207 set up.

On yeah! For some reason I always think that Renix Tbi started in 87, but it was 86! So I can source that from xj's so I'll actually maybe find one. Would the CPs from a manual be any different from the auto's CPs? Basically all I know about the CPs Is that it plays a role in ignition timing, and I had to put it back in when I rebuilt the motor a while back. Also is the 85 904's electronically controlled at all? Because I don't want to get into a wiring nightmare! I think I will move forward with the 904 if possible, and keep the things close by to go ax5 if I hate it.

I have thought about using an ax5 but my reasons for wanting the 904 are: It works, I already have it, I was going to use the truck to tow around a couple atvs ( it is to my understanding that automatics increase tow rating a bit) also automatics are just easier to use when towing in my experience. ( I do prefer sticks tho) and its only got 70k miles on it. Is the 904 such a dog that it's crappiness out weighs all things above? Also do you see enough benefit in me making a write up on this swap that it would be worth the effort?

Crap, I thought maybe I could just take both axles to "my jeep guy" and have him swap em for me for cheap, doesn't sound like it would be cheap from what you say. Thanks for the reply. Pete do you have any other insight on the myriad of questions ive posed in the OP?Would you use a mig or a stick welder on the spring perches? I have friends who can weld.

When you recharge the system you will have to research what oil you have to use, as they are are not all compatible. In my experience r12 is vastly superior to r134, so I would continue to use the r12 system as long as possible. And just plan to purchase the whole system when it goes bad. Air in the system will make it go bad fast (been there). Hope I helped.

I basically have the exact same truck, I'm not sure what gear you are running but mine is 3.55. I only run regular, I run havoline 10w30. I drive 10 miles backboards and city, and then 15 miles hwy every single day and back again. I average 25mpg in the summer, 27 mpg winter (ac?). This is with the spare the jack, a gallon of coolant, at least one quart of oil, bed tool bow with a bunch a crap in it. A big fuse kit. Jumper cables, and a lot of other stuff that is required when you drive an 87 model truck as many of these items are consumed on a daily basis. This is just my experience w/ my mj. If your truck has 3.73 gears your mpg sounds about right, from what I understand.

:fs1: could the guts be swapped, because my welding looks like chicken poo, and holds almost as well.

Old MJ exhaust is in pretty good shape, so I hope it won't run into anything during the swap. Hadn't thought of that, good call! The axles should be a direct swap though right? thats kinda my thought as well, but as for now one vote for shimming.

I have a 1987 MJ 2.5 ax4 2wd (d35 rear 3.55 gears) w/ rebuilt motor, and 130,000 miles on everything else. I also have a 1985 xj 4x4 with a problematic motor, the xj has: 2.5 a904 np207 d35r/d30f (4.11 gears). (only 70,000 miles) So I am planning on taking the axles and tranny and tcase from the xj and putting them all in my truck. Is there any fitment issues since the firewall was moved between the years of these vehicles? I am under the assumption that: The transmission will bolt up, as I know of no bolt changes from 85 to 87. The front driveshaft will work, as the distances should all be similar to the from xj to mj. The axles should basically be a direct swap, and I will keep the xj's brakes, as the front brakes will not swap from the 2wd front axle to 4wd front axle. Am I right so far? I am not sure about: Exhaust routing, looks like it will work, but looks and does are many times different. The MJ only had 904's in 86, so the firewall moved in 87, and the np207 was dropped somewhere in there, so I am not sure if any 4x4 mj rear drive shaft will work. Will I have to have one built? Also, will the tranny/tcase mounts swap from xj to mj of these years? Should I take the xj's suspension parts? They look like the same ride height, not sure if the rear parts are the same anyway. Will there be any steering issues? Will I need to rob the xj's steering components? The mj being manual (ax4) and going to automatic, I know there is some engine to transmission brackes to attach to the 2.5 in the mj (a long rod, that I am unsure of the function of ((not an auto guy))). Is there any electrical parts that control the 904 that needs to be brought over? This may be a lot more complex than I am thinking it is going to be. Would it be worth the money to just switch to an 4x4 version of an ax5? (i would rather not, if possible, as I have the 904) A little off topic, but related. The front axle on the xj is a vacuum disconnect axle, is their any mpg advantage to not just shimming it to be engaged all the time? Not that I am expecting an answer to every question, just if someone happens to know, and can help, I would really appreciate it. If this will work, I may try to do a write up w/ pictures if it would beneficial to others... If I can get this to work, I can stop lusting after new compact 4x4 trucks, and save some money! Also note: not terribly concerned with the strength of these parts as the truck is a garbage truck first and for-most and there aren't any rocks to climb to get to the dump. So I am not terrible interested it a stronger rear axle or tcase or tranny, for the purpose of increased durability off road.

Well it sounds like from some of the other posts that your header pipe configuration may be year specific. When I was racing compact cars we used 4 to 2 to 1 headers on automatic trannied cars, mainly because it left the power band alone, and just allowed you better flow. But didn't do anything radical enough to mess up the balance between shift points and power band usage. For manual trans equipped vehicles we used 4 to 1, because it shifts a lot of the usable power to top of the power band. I mean you had to rev the pee out of 'em to get to it, but we were anyway. You would sacrifice a little bit of torque to really tear through the top of the gears, and as long as you kept the rpms from falling too far you could definitely tell a difference. The only exception to this was on vehicles with a "cliff face" in the power curve (meaning that you are looking at a dyno chart and its relatively level until a certain rpm and then its all the power all at once. Some engines like the Hyundai Beta engine was a super fast revving engine that tore through the top of gears like no bodies business, so the power was in danger of being moved out of reach with a 4 into 1 header, so 4 to 2 to 1's were a better choice for those engines. To make a long story short, I thought maybe your were gonna street race it some, or maybe do some dirt drag, or maybe even some truck class autocrossing. Hypothetically, if you put one on your truck one day, and the other on their the next your "butt dyno" wouldn't be able to tell much difference, so don't worry yourself about it. Because it really only matters if the following sentences sounds like to you would be doing. "I came out of turn 3 banging on the rev limiter in third" or "man, at the top of 2nd I was about to reach 60, and it felt like the motor had more to give, but I ran outta gear before I could get there."

I have not been able to find a write up specific to this project. Does anyone know of one. Cause the carb is the biggest POS I have ever encountered! The choke on it maddening. Thanks for the info, jimoshel.

My 2 cents. Edelbrock's six into one header is pretty nice and seems to be designed for your performance level. I like all the pipes going into one. It seems like a 6 to 2 to 1 set up would just slightly lower your powerband and increase torque mainly. While a 6 to 1 seems to help rip up through the top of the powerband. As far as the muffler is concerned, with quality built mufflers the more noise the more flow. So just find the best balance between performance and what your ears/local police can stand. It is possible to build more torque with more restricted exhaust system, but that direction never seems to pay as much as more open and consequently louder. But really unless you are planning on forced induction all gains from and exhaust system are pretty minimal in the big picture. (disclaimer: this is all based on my limited experience racing cars with inline engines.)

I have a 85 xj, with 2.5 carbed. (I hate this carb!) I also have a 87 mj 2.5 tbi. I really like the tbi set up. So: is it feasible to convert the xj to tbi like the mj? I know I will need from the intake manifold up. I will need to switch to an electric fuel pump, and I will need to get all the wiring. What else? Or: would it be better to just get a reman carb and put on it? (because the one that it is on it is never happy.)

Good call. The clutch master cylinder was empty, I had so convinced myself this wasn't the issue that I didn't even check originally...lol! So the truck hasn't had any shifting problems since I filled it up. Now however it seems I have a really slow leak that runs down on to the harness for the fuse box. So now I have all kinds of stuff that intermittently doesn't work in the truck. Awesome! :headpop:

Certainly hope its the fluid, because the clutch only has about 2000 miles on it.

(I will check both but...) Do you mean clutch fluid (brake fluid if I'm not mistaken), or gear oil level in the trans?

3 times on my way home yesterday (25 mile trip) my shift lever would refuse to into any gear after the transmission reached neutral. After pushing attempting to shift to whatever gear I wanted several times, it would finally shift and would be fine for several miles, then it would happen again. I think the clutch is releasing, because there is no grinding, and I rode with my foot on the clutch down a 3/4 mile hill trying to shift out of neutral and into any other gear, and it finally went into 2nd (after I had slowed down quite a bit.) Where should I start? I was kinda thinking syncros, but I am pretty tranny challenged. BTW: Truck is a 87 MJ 2.5 litre 2wd 4speed.

I believe the switch from ba10 to ax15 was made mid year 1989, so you could have either, if I am not mistaken. Unless I have missed something the inline six never had a AX4/5 transmission however the GM 2.8 V6 did but that was stopped in 86.

A product called remove-it. Made by chroma graphics out of tennessee is a great product also, easy on paint, and easy on you, but when it weakens the adhesive it leaves a greasy residue, but it is easily cleaned.