Just trying to evaluate my options if I can't fix what I have.

seems like hotwireauto has a stand alone harness for around 1k.
I did a little looking, for around 350 I can get the trans and 150 for the computer, so for around 1500, I get the OD trans and "factory" efi.

any drawbacks other than expense?
it seems about as much as FAST or Holley for their setups.

I built the harness for my 1938 streetrod truck using a 360/408 magnum and a 1995 A-518, 4 barrel t-body, Stock ECM and injectors. It aint that hard, but it is time consuming. Factory electric service manual helps with pin outs. I started with a stock Mopar harness and a Ron Francis fuse panel and a few Ron Francis wiring packages. And a few beers.

so my stuff is from a 2000 durango.
odbII, a little harder, unless I want to retro it all, since the plugs are different from 98 and back.

I was hoping for a more direct swap.

I used a 1995 harness and a 1999 engine. The OBD-1 harness was pretty easy to reverse engineer. The engine control wiring is actually very self contained within the donor engine wiring harness. I think I only had to hook 3 wires up to the vehicle when I was all said and done. I did snag the sensors off a 95 engine from the junkyard and had to drill and tap the intake manifold on my 99 engine to fit the 95 temp sensor. Swap is turn key, starts and runs like a champ and the swap was dirt cheap. I used a manual transmission. I tried at first to work with the OBD-2 harness/ecu, but it proved to be needlessly overcomplicated and messy in addition to requiring reprogramming to run without the body computer. OBD-2 can be reprogrammed to compensate for modifications, in my case this is not something I'm interested in doing, but for a hot rod it might come in handy. However the options for reprogramming the stock ecu are very unappealing to me, it's not the same as having a stand alone aftermarket ecu. The way I understand it is you have to email your calibration file to some guy, he edits it and emails you back. I don't fancy the idea of needing to rely on someone else like that. However stock type ecu would be your only option for controlling a 96+ OD transmission.

probably out of luck junkyard searching for a pre 96 5.9.
I could live without the upgraded transmission. just trying to see where to best spend my money if I have to do this all over again.

looks like I could get back into a carb for around 700 with a correct magnum intake and carb. would have to find the kick down stuff again, but I have an old unilite sitting on a shelf to get me past the distributor issue.
ugh, forgot, would have to get a new regulator too. or new pump.

We installed a Hot Wire EFI for a 97 5.9 in a 57 Dodge wagon. The 97 has the computer controlled trans. We bought a used engine, trans, engine wiring harness and factory computer. We sent our engine harness in to Hot Wire along with the money, and the harness they returned is very nice and is pretty much stand alone. There are only 4 wires you have to connect to your vehicle, but there are also wires included with the harness to connect to gauges and other things you may or may not want to use. The harness has the relays and a small fuse box included and they are wired in, it lays across the motor very well and connects to all the original 5.9 sensors & trans sensors & connections. The harness is long enough to reach inside the car (drill a 2 1/2" hole). We mounted the computer, relays & fuse box on the trans tunnel under a consel.

We ran into an issue because we had updated the body wiring from the 57 to a mid 60s harness. The Hot Wire kit we had made was for the 57 wiring (as to our instructions. Oops!) The tech line guy was great, and when we discovered the issue, the hot wire system worked flawlessly. We have only put a few hundred miles on the car since the Hot Wire kit has been installed (the car is in progress).

I would not be afraid to purchase another Hot Wire kit. I suspects if my son comes up with a late model Hemi, we will be ordering another kit from Hot Wire. Gene

What did you have to do about gauges, speedo and shifter to use the newer transmission?

I used a Hotwire harness for my 5.7 Hemi/NAG1 Mirada, and it works great. Very easy install, too.

same question then.
how did you deal with your gauges, speedo etc... since they aren't provisioned in the newer transmission.

I used a Speedhut GPS speedo and gauges.

We installed an aftermarket digital dash, because that was what my son wanted.

The Hot Wire kit provides wires in the harness for the gauges. You use as many as you want, or as few as you want.
We simply changed the sending unit for the water temp to match up with the gauge we used.
Oil pressure gauge on the car was mechanical, we added a "T" so we could use the stuff to attach to the OP gauge and retain the connection for the computer matching op sending unit. I see no reason you couldn't switch the mechanical set up we used with a different op sender to match your OP gauge.
Fuel gauge was unaffected. The Hot Wire harness does provide a power wire for the fuel pump through the ASD relay.
I suspect you will have to do a digital speedo or come up with a way to get the mechanical speedo to work from the digital input.

Have you checked on the Hot Wire website yet? They are very good at what they do, they can answer all your questions. Since they are building a harness to your specs, they may be able to accommodate some of the stuff you already have. One of the questions they asked was which trans were we using. Gene

Thanks, I may give them a call.

I used a Hotwire harness in my '68 Barracuda 5.9 conversion. I skipped the computer controlled transmission and went with a 200R4 with bellhousing swap. All my gauges are rebuilt factory units keeping the harness a simple plug and play affair. I did use the 2000 EFI injector connectors and an OBDII ECU for a 5 speed Ram pickup.

My tuner sends me tunes to download into my SCT tuner and adjusts them based on my wideband readouts. After reading all the tuning headaches and hoops guys running other systems have to go through, I'm happy I went with this plug and play system. It's great.

Building an EFI fuel system has gotten a lot easier over the past few years too.