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Unread 11-09-2009, 02:01 AM   #1
Russell_Goodall
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Swap a 3.9 magnum into the yj

Hey guys i got a 97 dodge dakota the whole truck for a donor just wondering if anyone has swapped one into a yj. and if so if any one knows some good resources to look into its a 92 yj so its obd1 and the dakota is obdII so i dont know howmuch that will affect but i also would like to keep it a standard the dakota is a auto but they both have the 231 so souhldn't have any transfer case problems thanks for any help

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Unread 10-23-2011, 05:38 PM   #2
czjeeper
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You are going to have the same amount of work as doing a 5.2/5.9.
You might as well do the 4.0 swap, it's much easier.
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Unread 10-23-2011, 07:00 PM   #3
Firefyter-Emt
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...but he already has the Dakota. I assume that is a big factor when deciding to use it as a transplant candidate.
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Unread 10-25-2011, 01:50 PM   #4
bmgadg
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I wouldn't, it won't be much if any of an upgrade. Go v8 or stay 4.0 inline 6 in my opinion.
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Unread 10-25-2011, 03:21 PM   #5
JeeperDon
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Quote:
Originally Posted by Firefyter-Emt View Post
...but he already has the Dakota. I assume that is a big factor when deciding to use it as a transplant candidate.
Sell the Dak and move on. Free is not always the best choice.
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Unread 10-25-2011, 04:40 PM   #6
timatoe
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I agree with Don, sell it. I'd try and pick up a 1500 Ram with the 5.9 if you're set on the swap.
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Unread 10-25-2011, 07:38 PM   #7
5.7YJ
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I agree with Don and Timatoe, that 3.9 is not worth the effort. If your going to stick with a Dodge engine, find a 5.2, 5.9 or a 5.7 Hemi.
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Unread 10-25-2011, 07:58 PM   #8
deathtrap
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I say sell bolth the dakota and the wrangler and buy a nice 92-95 4.0 wrangler with the dough. you will be miles
ahead. unless you just want a project to work on.
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Unread 10-25-2011, 08:07 PM   #9
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As Novak say in a lot of their stuff....
Just because you already have it, doesn't make it a good swap candidate.

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Unread 10-26-2011, 09:52 AM   #10
Jones-Maryland
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I have considered the same thing and disagree with the consenses that you should forget it. I have a 91 dakota that my daughter totaled. I put a new engine in it last year (before she wrecked it) so has less than 10K on it. Even though its "free" I would still have to find an Ax15 with the right output shaft to bolt the xfer-case to it (its a 4x2 with a Ax15). Though even with a doner full size v8 truck would still have the transmission issue (depends on the truck), and probably need to rebuild the engine. I don't have to have a v8 and the v6 would be plenty of power for my needs. My 2 cents is go for what is right for your needs and pocket book. And if you put the v6 in the right place (engine compartment wise), you could always upgrade to a dodge v8 later, some wiring and computer changes.
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Unread 10-26-2011, 10:18 AM   #11
Spuznick242
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Alright so your set on using the Dakota 3.9L...to go to an AX-15 your going to need an adapter plate, Novak should be able to hook you up with that but another option is looking at other transmissions that have that shaft that dont need an adapter or what tranmission is used behind the Dakota 3.9L that's a standard and would that be able to bolt up to the NP231.
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Unread 10-26-2011, 11:30 AM   #12
Jones-Maryland
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To clarify, my Dakota already has an Ax-15 in it, no adapter needed, only need to change the main shaft to a 4x4 version to mate to the NP231 (eaisier said than done). Now with any engine swap there is all the mounts/radiaor/wiring/stuff that's really where the details and pain are.

Can anyone clarify this. I have read that the 3.9 bellhousing is the same as the 318 cuin. If so an upgrade to V8 later is a possiblity.
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Unread 10-26-2011, 12:06 PM   #13
Spuznick242
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Ohhh. Alright. I thought you wanted to swap in an AX-15 but if changing the main shaft to a 4x4 version then just trade or buy a junk yard 4x4 tranny that'll mate to the NP231. As for mounts, my experience is cut them off of the doner truck and use them but it depends on the situation and if there is any aftermarket support avaialbe.

I'm planning a 4bt swap in my project jeep...this is all stuff you have to research and findout yourself, especially for doing an odd ball swap like this, that not many people have done before. Google and the search on the forum does wonders, my best be for you is to try to find someone who has already done the swap and listen to what they have to say, if you cant find anyone search each and every part and figure out what it's going to take to make them all fit together and then fit in the jeep. Also find weights and demensions on stuff as well...it's all about the details with swaps and your the only one that can fit the swap to your needs and wants.
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Unread 10-26-2011, 12:54 PM   #14
SunDevilJeeper
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4.0 radiator, 5.2/5.9 magnum, AX15, 231... done.


If you're going to put that much work into it, might as well go for some Mopar muscle. You'll just need the 3.9 bellhousing and IIRC an 11 inch flywheel... something about the pilot bearing, but that's it.


There are a a handful of guys on here who have done the 318/360 swap. Several like me, are in the middle of one. The 4.0 radiator will cool the 318 perfectly fine, and the AX15 will handle a 5.9 so you'd be set with the setup I mentioned. As for the radiator cooling the 5.9? I don't know, I don't need a motor that big. I'll just stroke my 318 someday if I wanna go bigger.
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Unread 10-26-2011, 02:38 PM   #15
Jones-Maryland
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Sorry I didn't mean to jack this thread from Goodall's orginal question. So please help him out with this swap.

So his Dakota has the 3.9 v6, automatic with a NP231 . My question; Is the Dakota 4x4 a left hand drop? if not he will need to use his jeep's np231 and bolt it to the dodge auto he already has, though if output shaft on the trans is not the same (probably not since his jeep is a 2.5) then he will have to swap out the input shaft from his jeep np231 with the one from the Dakota.

Also, may need to go to a bigger radiator say a jeep 4.0 to cool the v6.

As for wiring the computer I can't help there. With my skills that's the pain part.

I assume if you position this setup with the xfer-case in the original location, and position moter mounts accordingly, he won't have to get new drive shafts.

And there may be enough room in from of the v6 to pull it in the future and drop a v8 in its place, theoretically it should bolt to his trans, possible!
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