I have a 89 3.9 with 109000 miles, Can u tell me what all you had to do to do the la 3.9 to magnum swap. I've ran across a totaled 99 dakota with a 5.2 magnum with 158,000. Im thinkin about buying the whole truck and swappin everything over. The tranny bad in the totaled truck but I just had my tranny freshly rebuilt and beefed up. It should work and hold up to extra hp and torque right? I can get it for pretty much a steal. is it worth it and what should I watch out for, how hard is it, and what kind of wiring do I need to do. I'm well mechanically inclined but a amateur at wiring so thats the part I'm really skepticle about... Please help, I've checked all the FAQ's and searched other threads and can't find anything on LA to OBDII Magnum swaps.

 

The V6 transmission will work for the 5.9 but don't trust it to last long. It didn't come on that engine for a reason, which is it can not hold up to the torque that it puts out.

The reason you cant find much info is because no one that has done it has written up a post on it. So your going to have to piece it all together yourself.

From what I know is the motor mounts are the same. That will be all the easy stuff. You will need to swap over all wires, computer everything. Without the exact transmission it came with the computer will be throwing out codes.

The radiator support is to close to the engine. You will need to do an electric fan upgrade or you can swap out your radiator support and grill and hood for an 91-96 Dakota.

The easiest way to deal with all the wiring is to get a complete setup from a 92-95 Dakota/ Ram.

 

motor mounts may not be the same....the early magnums had ears like the LA plus the pad on side of the block....all v6 used the side pads...

 

The magnum motor mounts, both V6 and V8, will line up with the LA 3.9L block's side mounts. It is the early LA series V8 engines that don't have the side mounts (except the 1991 V8 318's).

 

Even though my transmission has been rebuilt with planetaries from a V8 Tranny and not even 100 miles?

Thats why I'm posting and asking questions. So maybe I can catch someone that has the experience of doing this and it will be shared with the world

The wiring, computer and everything is really what im confused about.. as far as the code goes, that doesnt really matter it's a 89.

Personally I don't really care for the look on the 91-96

I have access to the whole 99 dakota the 5.2 is in

 

Anybody? Please Help!!!

 

I know that the swap can be done with the 93 up, use computer and wiring harness with the v8, it'll plug up But i think the harness is different on the 89,also you'd need the fuelpump and lines from the 99 differnt fuel pressure don't know if the tanks will swap or not, Not saying it can't be done

 

Its not the planetaries that will come apart, its the clutches you'll burn out. If you want the v6 tranny to work behind a v8, you need high performance clutches and a shift kit to limit how much the clutches are allowed to slip.

Well like Crazy4x4rt said, the info hasn't yet been posted, and and similar questions get asked all the time on here... if the info hasn't been written up yet, we haven't had a member who's done that exact swap and is willing to share it.

But just a word of advise... Crazy4x4rt gave you some answers and you chopped up and beat down his post like you don't believe him... thats not a very good way to make others want to help.

Oh yes it matters a whole heck of a lot! If an OBDII computer throws a transmission code (and several other vital codes will do the same thing), it will throw the computer into "limp in" mode and the engine won't run right and you'll have a serious lack of power. You should probably read up on OBDII computers before you try to swap one into your truck. They are nowhere near as forgiving as OBDI computers are.

But to shed some light on what kind of wiring needs to be done, I will say this... don't expect the any of your connectors anywhere along your harnesses to match up with any of the '99s connectors. So obviously, since you're swapping engines, the '99 engine harness can stay as is, but the '99s body harness will somehow need to be spliced with yours to make everything else work (lights, gauges, etc.), and that is what you will probably have to peice together on your own unless someone comes on here and shares the information we've never gotten.

Well, he gave you two options, if you don't like one, then take the other... the fact is the engine won't fit without you changing something. Do some research on the Shelby Dakota, and you'll see how to fit a small block v8 into your engine bay. Or just listen to what Crazy4x4rt already told you, and put an electric pusher fan in front of the radiator to make the space available.

He just made that comment because the '92 to '95 wiring would be much simpler and allow you to use your transmission. It will also make hooking up all the other electronics (non-engine related) much easier. The '92-'96 are still 1st gens, so if you come across a connector that doesn't fit, you can go get that particular part off of a '92-'95 that will plug right into the new harness and fit right in your truck with no other modifications. If you really want to try to splice your '89 and the '99 harnesses together, good luck with that.

Seriously though, it sounds to me like you have done no research on this subject. Sure, forums are a great place to ask questions and get help on problems, but you won't be doing yourself any good if you limit all your research to forums. You should start by researching away from forums, and then come here and see if we can fill in the pieces you still aren't sure about.

 

Good point... throttle body injection runs at a higher pressure than a carb, but still much lower than multi-port injection. You will need the pump assembly (and possibly the tank) from a '92-'96.

 

Have you considered going to a carb? Eliminates a lot of hassles.....