Is the 93 Dakota 2WD or 4x4? If it is 4x4 it will have torsion bar front suspension, instead of springs, so it won't be interchangeable. Motor mounts will be different, as they changed for a Magnum engine, if you put a Magnum engine into your 1990, you'll still need to use the LA style engine mounts. Also 4x4 and 2wd engine mounts are different.

 

Its 2wd....whatever donor I use the prerequisite is v8 93-95 2wd auto...I may have found a running 94 that fits all the above...trying to avoid 4wd as I don't relish changing out drive shaft of 727 as I believe you need to do to convert a 4wd 727 to 2wd.

 

As for mounts thanks for the clarification...I know blocks are similar and some have bosses for both but I get confused as to la to magnum or magnum to LA and what's compatible.

 

I'd stick with that 5.9 Ram if i were you, mainly as it has everything you need. The wire harness you can un-tape and re-adjust or extend what wires you need to.

 

I didn't have a donor vehicle, I've been putting mine together piece by piece w/lots of junkyard trips and RockAuto purchases. If I had to start over, I'd go with a similar Dakota V8 as a donor. Many pieces you're needing will be there, and some things, like the fuel tank, can be a pain to get any other way. There will likely be many things you'll just be glad to have a replacement for (that broken hood release cable or cracked tail light).

The oil pan will work on your 5.9, I think it's the pre-Magnum engines that differ in that area. Also, you can use the fuel rail, injectors, and computer from the '93 5.2. As long as they're from the same year then the flow rates will be correct for the computer.

 

Why? Wouldn't a 5.2L Dakota have everything including the correct harness, since I'm using a different crate 5.9L? Plus it has things the Ram doesn't like the correct springs, fuel tank, and possibly other stuff.

 

This area I'm reading conflicting information on. There's a debate that the 5.2L pcm doesn't give the best performance on the 5.9L. It will work, but not optimally. So, that leads me to wonder is it just the PCM that's different, or are the injectors different also? I can find a 5.9L pcm easy enough or go with the Mopar Performance PCM, but are the injectors different. Guess, I'll hop on a few auto part sites and see if the part #'s differ for the same year between a RAM and Dakota.

 

Just collecting my thoughts and maybe this will help someone in the future. I checked part numbers at Advance Auto for 1993/94 5.2L Dakota and 5.9L Ram W150 and they have the same Intake manifold.

However, here's the kicker, so be careful.

The 93 Dakota 5.2 injectors are the same as 92, but different than the Ram. The 94 Dakota injectors switched over to the Ram injectors and they are all the same for both 5.2 and 5.9. So, for mix/match purposes unless you want to buy 8 new injectors, a 94/95 donor is better than 93 in the case of a 5.9L swap. I wonder if that explains somewhat the performance issues with some 5.2L PCM on 5.9L's? If it's a 93 5.2L PCM then it wouldn't match a 94/95 injector on a 5.9L.

 

It will depend on the fuel system. I believe the Dakota went to Returnless in 94, and the fuel pressure changed, so the PCM tuning and Injectors would change because of the change in fuel pressure. There was a debate about this not long ago about if a PCM from a returnless fuel system can be used on a return system, and while the PCM doesn't care about how the fuel gets there, it does care about the expected pressure, so you need to make sure your fuel pressure is correct for the PCM you are using.

Also, on the return system the fuel pressure regulator is adjusted by engine vacuum I believe, and will change based on throttle position (fuel pressure is lower at idle than at WOT). The returnless system will have a constant fuel pressure, and the PCM is tuned for that.

Some people have gotten the 5.2L PCM to work with a 5.9L by converting to a return system with an external pressure regulator, and modifying an Intrepid pressure regulator to deliver IIRC about 60PSI.

Just found the thread, here read this, it has alot of info:

https://dodgeforum.com/forum/1st-gen...-question.html

 

I'd read that thread a week ago, and much of it didn't make sense then, but it makes far more sense now. Explains further why the injector change from 93 to 94 and why the PCM needs to match.

So, if I'm following correctly, the 90 vert I have will have a return style fuel delivery system... My options are:

Use a 93 5.2L Dakota PCM, fuel tank/pump and stay return, increasing pressure with an intrepid regulator

Use a 94 5.2L Intake, fuel tank/pump and convert to returnless, but use a 5.9L PCM

Use a 94 5.2L or any 5.9L (pre 96) PCM, but keep fuel tank/pump return style and add the intrepid regulator