I have a 2001 Dakota which will be the donor chassis going under my 56 Dodge C3 build prodject, but the 4.7 it has is at 203,000 miles on it and its not a tunable as the 5.2.

So I have a early 2000's 5.2 Magnum with less than 25,000 miles on it, as it was a factory rebuilt 5.2 that was in a Ram 1500 pickup that got wrecked. I'll be doing a bunch of mods to the 5.2 which should get me over 300hp at the rar wheels under the 56. But the question is how much of the 2001 Dakota chassis/engine harness can I use for the 5.2 Magnum in replacement of the 4.7V8. Would be great if I can use the Dakota harness and plug the 5.2 Magnum into the same harness. If I need to change some pins would not be a big issue. But if I need to change out the engine harness to make the 5.2 Magnum work. The link given here states the 5.2 Magnum needs only basic wiring to run:

https://www.youtube.com/watch?v=QJ19fZLppXs

I also have a 8HP-70 8-speed trans for the 56 build. All that is needed to make it work with the chassis is four simple inputs none of which are difficult to figure out. And the harness from Sound German Automotive handles nearly all of it. So just the wiring for the chassis to the 5.2 Magnum swap for the 4.7 may be the only challenge.

Andy, As I see it you need to merge 3 wiring systems together.
The wiring the 56 truck needs is pretty simple.The biggest issue there is most of the post 94ish stuff uses the buss bar that no longer uses off/on switches but now uses varying resistance instead.

The wiring to make the 5.2 EFI run could be almost separate, and may be easily converted from the 4.7. I suppose you need someone that knows what is different between the two motor groups.

Then you need to add whatever the transmission wants to see to function.

My plan is to use the 2001 Dakota in near entirety, all the electronics/wiring, all the cab features (power windows, power door locks, power mirrors, HVAC, power seats,wiring for lights, stereo etc, etc). Basically the entire Dakota, but with a much newer 5.2 Magnum and ZF 8HP-70 electronic trans. So in essence all of the Dakota chassis wiring will replace the original 56 wiring, modified and spliced or re-connected as needed. The 56 will have all new 12v LED headlights, and where possible I'll adapt the Dakota lights to the 56 cab/box. From what I have reserached the 5.2 Magnum can be set up with pretty simple wiring. And I know the 8HP requires only an RPM signal, brake light signal, reverse switch signal and setup for the torque range of the engine (Sound German Automotive provides the controller/harness for that). So if I can get the 5.2 to operate with the wiring shown on those video links in my post, I hope to be able to use the current wiring harness from the Dakota even if the 5.2 needs signals like crank position sensor, throttle position sensor, air intake temp sensor, water temp sensor, etc.

Maybe I can find out what I need for the 5.2 swap for the 4.7 by contacting the like of Dead Dodge Garage and Uncle Tony's from their youtube sites.

It sounds like you have a plan.

From past experience using Dakota wiring in old Mopar bodies, a 1990 version in my 48 Plymouth, and a 96 version in my 49 Dodge pickup (which uses the buss bar system), I can tell you the Dakota harness will be plenty wide for your 56, probably nearly 10" to 12" wider then the old dash. That is a lot of extra wire to stuff into and occupy an already crowded area.

The temptation will be to shorten the wiring harness. Before you do, I strongly suggest you per-determine which wires can be shortened with out effecting the Buss bar system that uses resistance as a basis of many of its operations. Switches that used to be on or off now change the resistance in the line, some for a momentary change. I have all those long wires from the intact Dakota dash harness shoved up under the dash in my 49. Its not pretty at all, but everything still functions.

One more note to add to the list of things I remember that caused a minor issue. The door jam switches that operate the dome light function from the 88-96 Dakota does not fit in the 49 cab, it is too long to function correctly. Don't know if that will be an issue with the 2001 door switches in the 56 cab or not, but I thought I would mention it. Its a detail that was put off as not a necessity, that I'm working through right now. I just installed a new headliner in my 49 and the over head counsel from the Dakota I had in the 49 before won't work with the new headliner. I have found that dome lighting in this day and age is not as easy as I thought it would be.

Yup, the plan is to not modify the Dakota harness any more than is essential to making the 56 a daily driver. I plan to use all modern headlights (LED) turn signals, brake lights, back up lights, etc, that will all plug into the Dakota harness connectors. Or I'll make minimal length jumpers to transition to the Dakota harness. I figure if I use as much of the original Dakota wiring and harness as possible I'll avoid creating my own issues when getting the 56 road ready. I also plan to use the overhead console and even the high brake light at the back/top of the rear window of the 56 (probably internal, behind the glass). I also have plans for a knee bolster/cover under the dash to conceal all the stuff that'll be under and behind the 56 dash.