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Hi I am doing a 5.2 magnum swap (engine is the same year as my truck)with a aftermarket intake and carb and i am planning on using the original transmission (auto)for now. Does anyone know if i will have any problems with the transmission working with the carb vs fuel injection? Any tips will be appreciated. Thanks
 

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Hi there!

A 1994 should have a 42RH/44RH transmission, so the only loss will be the overdrive enable - and that's actually not through the PCM, so keep that wiring and you should be good!

You may have problems with the TV cable attachment, but folks like Lokar make kits that can be fitted.

You may want to make it easier, and find a 727 to put back there instead. You'll lose overdrive, but depending on the carburator, you may be able to use off the shelf TV hardware (well, it'll be a "kickdown lever" instead.)

If you have cruise control, that may be hurt worse since the 1994 used the ECU to drive the cruise servo. You can hunt up a mid-to-late 80's cruise control setup (it spliced into the speedo cable) if you want cruise. If you don't, then ignore this *grins*

Speedo is electronic, but I THINK it's driven right off the VSS, so that won't matter.

Your biggest problem will be that the factory tach is driven off the ECU, not off the motor, and is 2 pulses per revolution. This isn't actually that hard to fix on a V8, with 4 pulses per revolution - a simple /2 gate setup will take care of that. It will still need the input cleaned up (so you don't get, say, 20 pulses per spark due to the ringing off the coil).

That covers most of it, I think.

Oh - while doing this work, if you don't grab some headers, at least find some 92-93 exhaust manifolds. They're bigger, and flow a bit better, than the 94+ manifolds do.

RwP
 

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Thanks, i went ahead and bought bigger headers and truthfully im not worried about the cruise control. That answers a lot of questions i had. Thank you
 

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Do be aware you may have to rewire the truck engine bay almost completely. Good news, the non-tach non-speedo gauges are just simple gauges, no problem with them. If the speedo causes a problem, you can use a 1992-1993 with the mechanical speedo and keep the tach (be SURE to get a wiring diagram for the year! Mopar kept changing the pinout!)

I'd do as many relays as I could up front for things.

You'll need a fuel pressure regulator to drop the 40psi(approx) from the fuel pump back down to a livable pressure for the carburator. May be worth it to find a tank and pump from one of the TBI trucks to swap in, so you can use an external return style regulator.

(Your truck uses an in-tank FPR, not as amendable to being swapped.)

Enjoy the fun!

RwP
 
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