first of many 5.7L swap questions

Discussion of the 5.7L-6.1L-6.4L HEMIs.

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southsidehacker
Posts: 4
Joined: Thu Jan 12, 2006 9:39 pm

first of many 5.7L swap questions

Post by southsidehacker »

I'm installing a 04 2wd truck 5.7L Hemi and trans into a 51 dodge car. I've already had a chance to weed through the factory harness and have a question regarding the speedo. What have you swappers used for a speedo output on the wiring harness? Secondly are typical 30A Bosch style relays capable of replacing the factory stlye relays (ie ASD,fuel pump, trans, etc..) Anybody have any sources for reprogramming the ECM's besides S&P. I'd like to remove all EVAP functions, cruise functions, and a few other things. Thanks for your help!
dodgetruck1
Posts: 6
Joined: Sat Jan 14, 2006 1:12 am
Location: Carson City, NV
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Hacked Harness?

Post by dodgetruck1 »

southsidehacker,

I have a 5.7L hemi going in a `67 D-100... it was originally an automatic transmission setup so I have two computers, one for the engine and one for the tranny.

I wrote S&P and they said I did not need a computer reprogram. Since I am switching from automatic to manual, they said it would be unnecessary. Unfortunately I don't know of another group who can do the reprogram, and it sounds like you will need it at least for the rear end ratio (unless you are keeping that the same? Seems unlikely that the truck ratio would work with the car, who knows tho... did they tell you what ratio the truck had?)


Hey, how far have you gotten into the harness? Are you able to share what you have cut out, found unnecessary, etc?

I hope to remove unnecessary wiring from the harness if possible and would really find any input you have helpful.

BTW, you'll need 49+psi from the fuel pump to the single input on the fuel rail according to the `03 Truck Service Manual. The EFI return line is in the fuel tanks on the trucks... and so is the pump. Summit has pumps which supply more than 50 psi that mount outside the tank but they are expensive, might be cheaper to go with the S&P custom tank kit for your project.

Kris W.

Regards,
Kris W.
`67 D-100, 5.7L Hemi project
`05 Magnum 2.7L
southsidehacker
Posts: 4
Joined: Thu Jan 12, 2006 9:39 pm

Post by southsidehacker »

Most of the harness surgery involves isolating the pcm from the underhood fuse panel. Carefull studying of the wiring harness and pin outs makes this pretty easy. My intentions are to keep everything about this setup stock! No headers, no CAI, factory manifoslds, and cats etc. As for the fuel tank.... we built a tank that accomodates the entire fuel pump assy from the Ram tank. This will hopefully make life easier! I guess I could always order a handheld to program the gear ratio right?
dodgeman66
Posts: 17
Joined: Wed Sep 17, 2003 11:22 pm

Hemi swap

Post by dodgeman66 »

I just got thru installing a 5.7 in a 2000 dakota and used the factory wiring harness. I didnt cut out anything because there is not much left after you hook everything up. I used the power module in thedakota for the relays and fuses and it all works great. I have not hooked up any gauges yet or a few other minor things but we have taken it down the road and it will roast the tires off. The dakota has the digaital dash so Im going to hook the bus and data lines to it and see if they speak the same language later on. Ive got to put one in a 1997 Ram now before I can finish everything on the (my sons)dakota. Im thinking about putting all my notes together on the harness and making copies for sale for anyone wanting to use the harness. Bill
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