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1999 Dakota 4x4 Hemi swap info/opinions

2791 Views 24 Replies 5 Participants Last post by  DADDYODODGE1
I have a 99 Dakota 4x4 currently with the original 5.2...I'm planning on installig a 5.7 hemi and have a a few questions....I also have my complete 2000 Dakota 4x4 with 4.7 as a parts truck as well....My main questions are.

1-which trans is best to use the 46RE currently in the 99 Dak or am I better to use the 45rfe out of the 2000 Dakota and then use the engine harness from the 4.7 as well?I'm thinking the 45rfe with no kickdown cable to worry about and seeing as it was used behind the 5.7 anyway would make life easier or is there a benefit to using a 46RE?

2-Is the stock trans crossmember etc retained in the stock position when installing a hemi using the aftermarket Holley conversion mounts?

3-Which year hemi is best?Can I run a newer eagle head or MDS engine and computer in my 99 truck?

This truck is in great shape and my daily driver...Not looking to build anything super radical just hoping to get some better fuel economy and the added performance is a bonus...So once I narrow down what engine,trans I'm going to use i can start accumulating the parts for the swap...I see the engine mounts and now Milodon 4WD oil pan and pickup are available so now is as good a time as any..

I'd like to stay with as many factory parts as necessary regarding the ECM and such just reflash it as I already have a SCT Tuner and trying to keep the costs reasonable if possible.

Any info is much appreciated,thanks... :)
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Ok. So this post is loaded with questions. But I will start off answering a few of them. The 46re never came behind a hemi. But the 45rfe did. And to match the two you just need to make a small cutout on the plate that goes between the engine and trans. As far as which engine is best, bigger the better right? But if you want the computers to be able to talk to each other, that's not the case. Unless you are going standalone or changing the entire dash out to a charger/challenger ect. A 2003 to 2005 ram. Or a 04-05 durango pcm and wiring will play nice with your electronics. But you will have to swap the cluster to an 01 to 04 dakota or 01 to 03 durango. Any ecu from the hemi cars or truck/suv 06 or later are a different bus system. They speak different languages... so best bet is any pre eagle, pre vvt motors. 03 to 08. When you get your ecu. Get the keys and skim. Shit I can go on for an hour on tips to go for and stay away from. Pm me. I will set ya down the correct path so that you aren't spending twice the $ for the same bs you can get the first time round in the junkyard.
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And sorry but making the 4x4 work, there are no off the shelf engine mounts, make your own oil pan/pock up tube. I believe milodon makes an oil pan set now, but the whole package is around $700. Around you proficient in automotive wiring. If not, last I heard you can get a custom wiring harness, but it will cost ya close to a grand. I'm definitely not trying to scare you off from this project. I'm doing the same thing in a 01 4.7 4x4 quad cab. But the learning curve is intense or expensive. Depending on how much you can do yourself. Pic of my latest test fitting as of this morning...
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I made my own motor mounts, I have my own oil pan almost ready to weld up. The only exhaust manifolds available for 4x4 ate the stock ram/durango stuff. No car on exhaust. Shit hits the frame. No srt shorty headers... booo! But if you align everything up right you can use either of the car or truck timing covers and accessories.
Getting ready to install 5.7 Hemi and 545RFE transmission into 2002 2WD Dakota. My understanding is no
modification is required on oil pan or frame with 2WD. Only on 4WD. Dakotas. Also does anybody do wiring
modifications to make wiring plug and play besides Hotwire. They have a 4 month back log after they receive
your wiring harnesses before you can get them back. I have checked for stand alone wiring kits, but have not
found anybody that makes stand alone units that also operate 545RFE. Any help would be appreciated.

Thank You Daddyododge1
Only stand alone type stuff I know of for the 45rfe is in the jeeps and a couple dakotas. My 01 had it. But I'm sure it need the bus signal and other inputs from the ecu to make it work right. Just never researched it. I do believe you have to either notch the crossmember or do pan work, even in the 2wd. And as far as the wiring goes.... yea. Make your own or hot wire are the only options I know of..and you have to remove your dash wiring to go with it if I remember correctly. But it has been quite some time since I looked into it.
Thanks for the info and reply.Only reason I asked about which trans is if the 45rfe was better than the 46RE...The 46RE is basically the old 727 with an OD unit added and computer controlled governor.I've had good reliability from both trans in Dakotas over the years so just thought I'd ask.

My Dakotas being a 1999 and 2000 still have the manual shift transfer case so I'm going to check and see what Ram models have the manual transfer case...I know the 2003 Ram 1500 did and the 2500 a bit later as well.Just trying to eliminate any Bus codes and such from using a newer system that has an auto transfer case.

My Daks are both pretty simple stock...Manual transfer case,rear ABS only and the ECM.not much to it.

So to start:get- 03-08 5.7..........I've heard the truck engines make the accessorries fit better?

2-Going to need to fabricate some engine mounts.

3-Ram or Durango exhaust manifolds sound like the only option for exhaust...No biggie,like I said this is a year round daily driver for me not a race truck.:)

I'll likely PM ya for some other tips when I get a chance.Much appreciate the input from all so far :)
I don't think you will have much of a problem with the transfer case. I'm swapping a 242hd in mine. Manual shift. And from what I see in the dakota, there is a separate computer to work that. So I will have to eliminate it and repair that wiring as needed. But for the older trucks, it's just not there. Just the wiring for the correct light to come on lol.
As far as to which accessories to use, it's kind of your choice. Truck stuff fits easier. But no car style intakes. I'm using the car stuff. I have plenty of room for the ac compressor. And the alt will sit just above the frame. The pic I sent earlier has the car manifold and timing cover on it. And just FYI. The older trucks will have to use the 01 and up brake booster. I have very little room with it as it is. And needed to go with the plastic valve covers and updated coils to get any for of room to remove the coil with the valve cover on lol
I just happen to have a complete truck engine. And a complete car engine. Well, missing the alt for the car. So I can verify fitment for both right now- alt. But I see how it fits. There are a lot of little things for both that are better or worse. For ease of things, go with the truck stuff. If you will be adding or searching for power later. Car us the way to go. But with my mounts, both fit and everything is aligned from the end of the crank, same as the 4.7 was from the factory.
I can't put the ac pump on yet. My org protype mount plate is too long. And I don't have an alt. But it will all fit. This is the car stuff.
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Oh. Here is a great read on the entire project thread. And I have taken a lot of notes from him and hemidak. Hemi-Kota Project DONE!
I can try to find it. But all they did was notch the crossmember and refill it to get structure back.
I have an 05 300 pan here. Problem is its front sump...
Seems that there are only two options on oil pan. Milodon, or make your own.
Just in the process of picking up a used hemi block for cheap.Figured it would make life easier when fabbing up some engine mounts when the time comes.:) Planning on pulling the engine out of the 2000 with the 4.7 and use that as the template to mock up some engine mounts.
Yep. Thats what I did. I just don't know if I trust the 4.7 perches to make the mounts. Factory 4.7 mounts are made of 1/8" steel. Factory 5.7 truck mounts are made of 1/4". And being that the hemi is 345hp while the 4.7 is 195. Almost a 100% increase in power. It makes sense that the mounts are twice as thick. So I'm just using my modified 4.7 mounts as a template to make bigger stronger mounts from scratch. My prototype 4.7 mounts are in the truck right now so I can't include them in the pic. But the steel in the following pic is 1/4" plate and square tube that I will make to match the org 4.7 mounts. I just know that these will not break when I get to 450-500hp. I'm planning on 400-450. Hopefully more. But not wanting really anymore than that. And this is my way of making sure my mounts are solid.
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As far as oil pan are concerned. As it is a question in this thread, and a main discussion piece, buy a milodon if you do not have proficient metal forming and welding skills. To make you own, you need a 5.7 and a 4.7 oil pan. You have to cut them both apart. Then straighten out the odd edges of the 4.7 pan. Then you can think about welding the pans together. After that is all done, then you need to add an extension and fit the pickup tube to fit the new pan. The pickup is made of stainless and the fitment needs to have the bottom of the pickup screen to pan bottom clearance of about 1/4". If you do not believe you have the skills to make that. Buy the setup from milodon. And it's going to be around $700. You have to buy their pan, pickup tube, gasket, pan bolts, and dipstick setup. If you go this route, be sure to check the pn# there is one for 2x4 and one for 4x4. The 2x4 pan will not fit correctly. There is a member here that helped them develop this pan. I'm really bad with names. So I cannot remember his handle. But I give him all the upmost respect for his work on this so we have the opportunity to just buy an off the shelf part for this kind of swap! Lastly here is a pic of my two pans I need to make into one. As you can notice they do not look like they could match. But they will. You just have to spend a lot of time to make them work. Second pic will be them sitting on top of each other to show the amount of bending/shaping you have to do to make them work. And after I make these into one, I make my fitted pickup tube. Then, after all that, I can try to set up the dipstick ti be accurate. So spend the $$. Or spend a skit load of time to make it all correct....
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And for you guys making your own mounts. There are a few things to consider.... remember that the center line of the crank bolt hole needs to sit very close to the original 4.7 motor. This means height and width or x, y and z axis for those that get it. Y axis or length, will be slightly off. But that cant be helped if you plan on using the 45rfe and not getting the driveshaft shortened... It's not as easy as you think. I understand that 2x4 mounts are available. But 4x4 are not. I may have the extra steel to make a set or two of mounts. Pm for details.
When yall get to electrical let me know. Cause your cruse won't work, stupid emissions shit, brake sensor, and a long list of ects... lol. Shit, I just need to write a book! Lol
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