Early Hemi swap wiring.

Hi, I really recently purchased a 1969 Dodge promotional NASCAR truck. It has a 2004 5.7 and automatic out of a 2WD pick up. Truck was built 10-12 years ago and stock wiring and PCM were used. It’s kicking a bunch of codes, stalls, and tranny will just shift with what feels like first and 3rd gear( limp-in?). After you clear the codes, it runs better and shifts good for a little bit. The exhaust was redone before I got it, and there are no cats and O2 sensors are gone. Original builder stated that it had cats and sensors when built, along with stock PCM. Truck also has a mild cam, shorty headers, and what appears to be an early MP carburetor type intake with stock injectors and an adaptor to mount stock throttle body to carb base.
What I’m wondering is if there is a better way to go with wiring and PCM than chasing down all the codes and deciphering someone else’s wiring. Thanks for any help or ideas. Jim

Sorry for upside down pic, not sure how to fix that, either.

The carb intake is worth some $ to someone else, if I were you I'd yank that, get a cheap truck intake and call hotwire, tell them the PN's of the computers you have and they should be able to reflash and/or tell you what you need to buy to make it work.

What’s so special about the intake? This is best pick I currently have of it.

They are low profile and not made anymore if I remember right. There are way better intakes out there now, but this intake will still sell relatively quickly if not priced to the moon.

Thanks for info, ill probly just keep it on for now, it fits the air box. I'll call Hotwire this week. Jim

Thats a neat truck, I see it has a nascar style air box through the cowl.

You need to see what codes it has. If something is broken a new wiring harness won't fix it. I'm guessing it worked when it was built. If you want to use that transmission you have no choice but to use a factory computer.

Yes, the intake is needed to line up the air box. Most of the codes are battery temp sensor type codes. 1 is downstream O2 sensor, and then it kicked out a “low, no voltage to trans control module” code the other day. That and some other wiring issues I’ve found make me think most of the problems are wiring/ground issues.
It is a unique truck, so I bought it. My father is a NASCAR fan and retired, so I thought I’d get him something cool to drive to coffee. Gotta make it senior friendly first tho. Lol
Here is an interior shot.

I would say the o2 sensors are your main culprit, cats no big problem. If you could keep it in warm up mode it would stay in the pc’s stored parameters and not go use the 02s. Maybe the pcm could be programmed to do that. Bad gas millage but it doesn’t look like you’re going on long trips with that truck! lol

I have an 04 Durango with a 5.7 rotting away out at farm, when it gets nice, I’ll pull cats off of it and use them on here. You’d be surprised how nice it drives down the highway. Has about a 3.9 rear axle ratio, with the overdrive, it cruises pretty nice. Has ceramic brake pads, those have to go! Jim.

Might be interested in some of those engine parts off the Durango. I have an 05 Dak that has the V6 and would one day changeover to the 5.7.

Sure, let me know what your looking for. Jim