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86 Transplant


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Hey guys i have an 86 4x4 lwb. The po put a used 2.5 ax5 and np207 out of a cherokee into it. Thankfully it all will be on its way out soon since the 2.5 just doesn't have enough power. Tomorrow morning i am supposed to go pull a 4.3 vortec for it. I am still not sure what trans and t-case i will be using with the v6 (any input is welcome). I will post some pics tomorrow night for any who are interested.

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welcome to the club.for the record the 4.3 isnt that great of an engine imo it has lots of power but it doesnt make any of it untill about 3-4 thousand rpm in my experience. the 4.3s ae reallty hard to work on to. i think it would be much easier to swap a 4.0 in.

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It's a lot of work putting a chevy 4.3 into a jeep. Gotta have ALL the wiring and do some fabricating, and you still won't have the torque and ultimate reliability, although a 4.3 is a good engine, that you get from a jeep 4.0. Besides, you might want to check with local laws. Many states say you have to have an engine that was available for your vehicle, and you can't have an older one, but only a newer one. Doesn't matter if a 4.3 is less polluting. The EPA is actually pretty stupid on these things. Anyway, I thought about a 4.3, but I would go 4.0 first. But, I plan on getting a 2.5 and begin building it with ported heads, cam, pistons, etc and bring in an about 160 hp 2.5 that will be LOTS of fun and hopefully not mean any worse gas mileage. Guess what. The EPA can't say a thing about that! Heee, heee, heee.

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If youre gonna swap in a 4.3, why not make it a 305, or a 327, or a 350, or a 383, or a 400???? Same amount of work, and chances are, youll have overheating issues with the 4.3 as well as any of the others. Now if you kept it down to a 3.1, or a 3.4, they would bolt up to your existing transmission. And there are ways to keep the injection with them as a stand alone system. A 4.0 would be easier than the 4.3 as you know all of what it would take to do the job, and everyone here would be able to help out, as its been done many times. The 4.3 has also been done, but its nowhere near being a bolt in and go situation. Good luck and let us know how it goes!

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Well things have went into a different direction over night. I'm really sick and the guy i was purchasing the engine from has other buyers for it so whatever. I was considering a 4.0 swap but the only inline 6 cylinders i've messed with are the 3.0 7mgte's out of 3rd gen supras. I will start looking soon for a 4.0. Any suggestions on years or models to get it from? Here are some pics of the truck as promised.

 

 

 

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Donor year doesn't mean squat when you're dumping into an 86.

 

Shoot for 91-95.

 

Regardless of year donor, you're going to need to modify the radiator supports, and possibly pound on the firewall a bit.

 

This is on top of needing to swap ALL wiring, dash and engine bay, along with all the cooling stuff, vacuum, etc.

 

Best way is to find yourself an XJ that was wrecked either from behind, or not too bad up front.

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Its more than just pull the old motor, and put the new one in. Don't know all the details, but i know a lot of people do. The 4.0 didn't come out until 87, so the engine bay is not set up to hold it.

 

Yea, fergot about that! Engine bay on an 86 not made for a 4.0. You could do a 2.8 v6 or the one built off the 2.8 but I forget the CID. Again, I have an 87 4x2 4 speed power nothing MJ. I rebuilt the 2.5 adding a camshaft made by Delta out of Tacoma WA that is one step up from stock, Header by Clifford Performance, and a single in, dual out Flowmaster. Certainly not anything like a 4.0, but my 2.5 runs quite well as far as I am concerned. An electric fan and a cold air intake might even help more. Might consider just rebuilding the 2.5.

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GM's later 3.1L and 3.4L V8s use the same block as the 2.8L that was optional in the '86 MJ. That would be an excellent candidate for a swap.

 

In fact, the later 4-cylinders ('91 and up) with the multi-port injection produced significantly more power than the throttle-body version. Not in the same class as the 4.0L, but a late-model 2.5L would require no physical changes to your truck, you would just have to graft in the engine room wiring and ECU to make it a complete conversion.

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GM's later 3.1L and 3.4L V8s use the same block as the 2.8L that was optional in the '86 MJ. That would be an excellent candidate for a swap.

 

In fact, the later 4-cylinders ('91 and up) with the multi-port injection produced significantly more power than the throttle-body version. Not in the same class as the 4.0L, but a late-model 2.5L would require no physical changes to your truck, you would just have to graft in the engine room wiring and ECU to make it a complete conversion.

 

I want to slowly rebuild another 2.5 for my 'manche and will use a later one with the increased hp, and then I can use a bored out intake body and a spacer in addition to cam, header, match the intake and head surfaces, etc.

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sorry to say that but late 86 were made to have the 4.0L in

upon doing the swap myself

 

no mod to the fire wall of the comanche

you need to empty the engine bay from the donor

I mean take EVERYTHING

 

if your lucky it will go in real easy

I pulled the engine the tranny and the t-case at once

and you'll need to mod the rad support and other things

and take the engine mounts to if you wanna know more PM me ill gladly answer your Qs

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