Harness For Putting New Hemi in First gen

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Yoox_II

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5.7L Hemi
A couple guys I've talked to about swapping a 2012 5.7 hemi into my 84 d150 have said that there are standalone wiring harnesses available for putting a newer, fuel injected, computerized engine in an old Mopar. I can't however seem to find one that is best for my situation. Again, it's a 5.7 hemi out of a 2012 ram, and it's going into my 1984 d150. The engine didn't come with the full harness, it's missing some important wires etc. So what do you guys think my best option is? Can someone direct me where to look? I've google'd, but it seems like a mid 80s dodge truck is not a common swap truck. PS: I've already bought the engine
 

Jimmy68

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This seems like a solid option however it involves keeping some of the carbureted workings, which I don't want. I want full, as close to stock 2012 hemi as possible, fuel injection.

Buy a 2012 truck and swap your body.
 
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Yoox_II

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I think I've come to a decision. The R-0023 from hotwireauto.com seems to be what I need to put my 5.7L Hemi and 545rfe trans in my 84 dodge truck. Search "R-0023 harness" on Google, or go right to hotwireauto.com and view their product list. On their front page it says:

"This is a self-contained engine and transmission control system that comes with its own fuse block and relays. In each of our harnesses all of the connections are labeled and placed in their proper location for ease of installation.

We can program customer computers or we can provide new, programmed OEM computers. We also have experienced technical support staff available by phone."

It appears as though this kit includes everything I need to get the engine running, (after its mounted and bolted on). I'll be calling them tomorrow about shipping to Canada, and hopefully purchasing it...
 

crazzywolfie

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they are expensive but most likely the best option. i doubt shipping would be an issue. i got a friend who ordered a magnum swap harness from them. i would almost be willing to bet it is under $50 for shipping. i am just not sure about taxes/duty or if that would even apply to the harness/computer. if anything hopefully they will ship it through fedex who try to collect taxes/duty after the fact and it is really up to you whether you choose to pay it or not.
 
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Yoox_II

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This project is stil alive and well, it's just taking a while to get stuff done. Unfortunately I will be keeping my 727 3speed auto transmission with the new hemi. If I were to use the new transmission, I'd need to buy a transfer case for it to attach to the drive shaft because the transmission is from a 4wd. Would a 727 tranny be able to keep up with a fuel injected hemi?
 

charonblk07

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F1-A forged 349ci
This project is stil alive and well, it's just taking a while to get stuff done. Unfortunately I will be keeping my 727 3speed auto transmission with the new hemi. If I were to use the new transmission, I'd need to buy a transfer case for it to attach to the drive shaft because the transmission is from a 4wd. Would a 727 tranny be able to keep up with a fuel injected hemi?



Yes it will, several people have swapped the 727 with a Gear Vendor OD because the 545 is such a weak transmission, performance wise.
 
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Yoox_II

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5.7L Hemi
Yes it will, several people have swapped the 727 with a Gear Vendor OD because the 545 is such a weak transmission, performance wise.

Interesting, what makes the 545 so weak?

Will my 727 attach to a gen III 5.7 with no problem or will I need a different flexplate etc?
 

charonblk07

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Interesting, what makes the 545 so weak?



Will my 727 attach to a gen III 5.7 with no problem or will I need a different flexplate etc?



The 545 is maxed out on its designed input torque with the hemi. The weakness is the 2p clutch pack which is used in 4th gear, a WOT downshift through 4th gear is bad for the trans even at stock power levels of you do it enough times.

The 727 bolts right up since it uses the same short block bolt pattern but you will require the correct flex plate and you can order them from places like Modern Muscle who have everything to do the resto swap.


Sent from my iPhone using Tapatalk
 

crazzywolfie

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if you are going to spend all that money minus well spend a bit more and at least try to get a 46RH transmission so you at least have the 4th gear. a gear vender OD unit would be nice but they are not cheap. they nearly cost as much as a megaviper 46rh costs. plus if you get a 46rh and in the future decide to you can a gear vendor OD unit to it and it will give it a double overdrive option. i don't know if there is really any point in doing that but it would be cool if you wanted to go very fast.
 
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Yoox_II

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As far as the computer ecu goes, I don't have one. I ordered the harness from hotwireauto.com but didn't get the computer from them, because it was an extra $700. I'm hoping to find a used cheaper one here at a junkyard. The hemi is a 2012, and I know that the computers are for 09-12 rams. Am I able to use an older ram computer with the 2012 ram? There is a 2006 5.7 ram computer for sale near me, but I don't know if it's compatible with a newer hemi. Obviously there would have been changes from 2006 to 2012 in what the computer is telling the hemi to do etc. Also, I'm confused about the gas pedal, I know pretty much nothing about what I need for the gas pedal to work. I've heard that I will need an all in one throttle peal unit from a ram or something

EDIT: and will the computer not understand that the hemi is bolted to a 727 trans??? I know the trans isn't electronic, it's fully mechanical, but I'm wondering if that affects what computer I'm able to get.
 

R/T_Fire

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Short of researching it myself, which I don't have time to do..... Take a look at a company called Novak, they do alot of wire harness conversion using the donor vehicle harness and making it work in the existing vehicle.
 
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