I am new to the site and have a couple of questions that i am unable to find answers for in existing posts.
First off I have a 1999 dakota sport 3.9L 4x4 5spd. I am looking to put in a 5.9L out of a 1999 durango 4x4 automatic. I have two questions that i have been unable to find answers to, first off is the balance of the 5.9. I understand that it is externally balanced and want to know it i need to make any kind of modifications to it in order to get it to work with my stock 3.9l transmission.
Second questions is which ecu do i use? will the ecu from the 5.9l automatic work with the manual transmission or will i need to find a computer from a 1999 manual 5.9? I would appreciate any help that you guys can give me, iv searched high and low for these answers and came up dry. thanks for all the help!

 

no 5.9 came with a manual(in the dakotas and durangos), so you'd need a ECM from the same year of Dakota with a 5.2 manual, then get a programmer to adjust the fuel tables for your larger engine.

 

Double check the specs on your NV3500 tranny, which is what I believe you should have in the 1999 Dakota for the 5 spd. It should handle it I think, but it will be pushing towards its upper limits I think. Other than that, the 5.9 is externally balanced by the flex plate in the auto or a flywheel in the manual. You will need to get a flywheel from another 360 or for the 360, you can find them new at Summit? I think. Other than that it should bolt up fine.

You should be able to use the ECU from the auto, but it might throw the tach light off if you have one in the Dakota.

YOu will, of course, need to wire up the extra two injectors for the 5.9, or use the wiring harness from the 5.9.

 

I must have posted at the same time as you Independent. I don't think he should have a problem running an auto ECM with the manual tranny. It might throw a CEL though, but will run it fine unless I'm completely off here. SO yeah, I guess if you go to pass emissions it might be an issue.

As for years on the ECMs, 1997-2000 won't work? I was under the impression that the next change in ECMs was done in 2001.

 

I may be way off cause I am still mostly asleep this morning but isn't there going to be a problem as far as flexplate/flywheel from auto to manual. I would think You'd need a flywheel from a manual ram. Plus, the NV3500 came behind the 5.2 so there really shouldn't be any issues using it with a 5.9 since their output is so close in stock form.

 

Thanks for all the help guys, i know the nv3500 is going to be a little stressed but what can ya do ill just have to play nice! seeing as we are talking about reaching the limits of my little v6 set up how well do ya thing the rear end will hold up if im not mistaken iv got an 8.25 compared to the 9.25 that came with the 5.9. As for useing the auto ecm with the 5spd throwing a code is as simple as pulling a light bulb as long as thats all it does is give me an annoying dash light. Anyone out there actually use an auto ecm with a manual transmission and can verify what dbilik said?

 

The stock Hp. and Tq. figures for the 5.9 are not much better than the 5.2 and the 5.2 came with 8.25's and nv3500's for years. unless you are specificaly thrashing this truck you shouldn't have any trouble.

 

im building the same truck and i have a parts needed and answers let me know. 97 360 5 speed 4x4!!! 9.25 front and rear 5.5'' suspension

 

Hey mtlrck! hope I got the name right. I'm looking to swap a 5.2 for the stock 3.9 but I found a 5.9 at the local pick-a-part, complete, for $240. I know the 5.2 will switch right over, motor mounts, exhaust, harness but I'm wondering if the same can be said for the 5.9? You mentioned back in April that you were doing the same swap and had parts lists and answers to questions. I need and have both. You still here? Thanks

 

...and oh yeah! Can I use the PCM from the 3.9 for the 5.9? I have read about splicing in 2 wires for the injectors. Still dont have a clear image in my head for this. Does the V6 PCM have places for the additional wires? If my truck is a '97, will everything line up and plug in if the engine is from a '96 Ram? Sorry for being so dense. I'm getting excited about this and I want it to go as smoothly as possible. Thanks