I have a '98 Dodge Ram 1500 with a 5.2L and automatic that my son totaled about a year ago (challenged a brick fence head on - no contest). The engine and tranny should still be good.

My father-in-law found for me an '88 Dakota 4x4 with a 3.9L V6. The V6 has a severe case of the knocks so it must be replaced. Other than that, it appears the truck is in fairly good shape.

I'd like to pull the 3.9L and tranny from the Dakota and swap in its place the 5.2L and tranny from the Ram but I'm not certain whether it's worth the trouble given the differences in electronics. I'm also not certain how the trannies differ in size though I'm sure the tranny behind the 3.9L wouldn't play well with the 5.2L engine.

If it's been done before (Gen 2 Magnum OBD II into an '88 Gen 1) and is a meaningful swap, what's the best approach? Replace the intake, fuel injection & electronics on the Magnum with older style intake & TBI? Rewire to OBD II? I can imagine rewiring would be a sorrowful exercise in futility but I have to throw out that possibility just in case.

If it's been tried before and determined to be more headache than it's worth, let me know and I'll look for a different route. I like the idea of having the Dakota 4x4 for hunting and I hate to let my poor 5.2L go to waste.

Thanks for your input.

 

I would recommend the swap, but your going to have to modify some other areas that may put it off for you. The fuel pump does not supply enough pressure for the newer engine so that would need addressing. You may need to update your fuel line to 3/8 as well. The radiator and everything should be adequate. Running the gauges will require some finess. It may be advantageous to run an earlier EFI system, but not the antequated TBI. Either way, you will have to figure if it is worth it or not. There is a swap by Mopar action in the sticky, but your swap will differ since you will need a pusher fan from the lack of space in front of the engine.

 

I would say it is worth the swap if you have enough time. The stock multiport fuel injection will be worth it. Just take your time with the wires. Don't cut any wires, and label where connectors go. Swap EVERYTHING needed over. Is the Ram a 4x4, if not then you will need a 4wd transmission to keep 4wd in the dakota going. The 2nd Gen. Ram section has a service manual that you can use for the wiring diagrams ect.

If you do it post up pics and keep us updated.

 

Thanks for the replies!

Unfortunately, the Ram is 2wd so it looks like I'll need a new transmission if I try going the 318 route. I've tried searching for more information but I'm not yet sure which way to go with this. I'd prefer fuel injection over running a carburetor but I think I could go old school with it and get it to run (gauges as you mention might be tricky). Would the 318 long block from the '98 Ram be useful or would I be better off looking for an engine from another first gen Dakota?

Thanks again!

 

The gauges will/can be wired easily, but you have to chase the wires and make it look good, hence the finess part. I used all the original gauges and senders for my swap with the exception of the coolant temp. for the fan. Costwise, going carb will cost the same as modifying or swapping an efi, so it is really your choice, but buying used carb equipment would lower the cost and increase the potential for repairs. The 46rh trans (a518) is the one you want. I think it was available from 91-95 in all the V8 chassis. However, if you were wanting somerhing different, you could swap the drivetrain from the Ram and include the ECM for the engine and tranny. This would complicate your build, but it would be different to see an 8 wire tranny in that generation truck.

 

From what I've read, the the Dakota fromt end was lengthened 3" to fit the 318n under the hood. I don't remenber where I saw the 3" comment, but here's one source...and a cool link...



What Shelby did in '89, Dodge did itself during 1991 with the addition of the 5.2-liter V8 to the Dakota's list of regular production options. Delivering 170 hp, the V8 was exactly the sort of power plant the Dakota had been crying out for since its introduction, but it was really only a hint of what was to soon come. In order to accommodate the slightly longer engine, the Dakota's nose was redesigned with more space directly behind the grille. The new engine and revised styling helped swell Dakota sales to 82,336 for '91, including the last eight convertibles.


http://www.edmunds.com/dodge/dakota/history.html