[Guest]

My old faithful 86 258,t5 dana 300 will probably need a new engine and tranny soon ,I am quite sure the Dakota uses an NP231/23 spline which should mean the Dakota tranny should bolt up to the Dana 300 without an adapter, if a person could dig up a wrecked magnum v6,I would consider this a pretty decent all around drivetrain, any thoughts on this ,I would sure like to here some opinions on this. thanks all.


Tommybear
86 CJ7
295 75R16 BFG ATS
REP 8000

 

[dorfs]

A 4.0 I6 is almost a direct swap, and has much more torque than the 3.9 Magnum. If you were going that route, why not just use the 5.2 or 5.9 Magnum? There is plenty of room. Your T-5 won't bolt to a 3.9 Magnum, but will bolt to a 4.0. You would have to use an AX-15, or the Dodge version of the NV-4500, or the NV-3500 to bolt to the motor without adapters. All three of these trannys came in the Dakotas and the 3.9's, 5.2's, and 5.9's use a common bolt pattern A Dana 300 case will bolt to all of these trannys, but the input bearing on the 300 will have to be changed to a sealed one, and the retainer will have to be milled away to prevent interferance with the extension housing seal. AA sells an indexing kit for about $175. that does just that.

Dorfs, '83 CJ-7, stroked 4.0 HO, NV-4500, Dana 300, soon to be 5.2 Magnum

 

[Guest]

I just completed a 5.2l Magnum swap last week into my CJ8. Dorf's right about the 4.0l being a better swap than the 3.9l,into the CJ. The V8 swap made more sense to me as my Jeep is pretty heavy and the 4.2l lacked power even with a Howell EFI kit. The 5.2l or 5.9l fit perfectly, and would be an easy swap into a CJ7 if you used a NV4500, NV3500 or a small case torkflite automatic, no adapters or modifications are needed to the t-case. If you try the overdrive automatic, the adapter Dorf mentions would be needed. I used a NV3500 wideratio 5-speed out of a 95 Ram 1500. Use a 95 or earlier EFI setup to avoid OBD2 hassles with smog. I used a combination of stock Jeep V8 CJ brackets and some plate to make the mounts,(Magnum engines only), but if you are a better fabricator, you could adapt the stock Dodge mounts to the framerails easily. The whole swap took 2 weeks, after I gathered all the parts, (2 weekends and evenings after work). The wire harness was the hardest part, but with the help of factory service manuals, a couple of scrap harnesses and alot of patience, it went well. The Jeep has more power than I hoped for, gets the same mileage as before (15mpg) and is much smoother and quieter also. I also sold off the old engine and trans for what I paid for the NV3500 and flywheel at the wrecker! Hope this helps you decide, good luck!