Aside from the tranny issues which are to be anticipated, I'm not too surprised about the rust situation you describe. Too many times have I seen seemingly pristine vehicles in the Great Lakes region actually be utter havoc under the chassis in terms of rust. Too many people in this area take trucks like this mudding or snow driving and wash only the body, leaving the undercarriage to rot to the point of breakage.

And I'm actually sluggishly beginning a rebuild of a 5.9 magnum I bought as a donor for a heart transplant for my older-than-dirt 97 ram. Given it will be a different displacement ive decided that the best course of action will be to carburate this engine... Which would leave me with an beaten up 5.2 magnum drivetrain, computer and all, that may also find it's way into a rat rod if I have my say about it. It might be a while till I get my rat, but its an ever present possibility.

So while there may soon be two confirmed magnum blocks floating around in trusted rusted's, I might actually decide to carburate the 318 when I get done with it as well, just for simplicities sake. it will almost certainly need a refreshing if not a full rebuild, and the marginal-to-immense displacement change might just warrant a carb.

 

If I were building this truck for just me I would've went with a pontiac 400 and a 5speed manual however that would require me to open my budget up a lot. Plus my wife said she would like to drive it, so automatic it is. I rebuild these 46re transmissions so the trans problem didn't bother me. As a bonus this truck has a posi rear end and i will be changing the rear gear to 4.56. Mostly because I enjoy burnouts lol.

 

Interesting, perhaps you could help with an obstacle I may face soon... When it comes time to transplant the engine into my truck, it will be lacking the fuel injection components normally fitted to the 318. My goal would be to have as little electronic control as possible, but am unsure of how to go about the transmission. Is it possible to keep it in operation using the computer without having any of the EFI components? I may also consider a manual setup, but don't necessarily want to do a tranny swap involving driveshaft/mounts/clutch retrofitting. So would it be possible to convert the auto trans to a semi auto and manually control the shifting myself like a paddle shift setup?

 

The computer needs inputs from various engine sensors to properly run the trans..... If you want to keep the auto, go with a 46RH trans. Their are kits out there that will control TCC, and O/D.... (you get both at once.... so, no TCC without O/D.....) Otherwise, manual trans is going to be the best choice.

 

That's what my first impression would have been, but have also debated which sensors could still be viable after the carb retrofit, for instance I know some carb manufacturers apparently offer throttle position sensors that mate to carbs, etc.

But id personally just rather have a manual setup just for the sheer control I would have over the vehicle's behavior. Are there any manual-valve-bodies that can be put on a 46RE that allow me to manually select gears? My crude understanding tells me that they only allow you to essentially LIMIT the gearing to a specified highest gear, correct me if I'm wrong.

but from your experience Id like your opinion on one idea in particular, which involves using either an aftermarket or homebrew electronic controller to basically hijack the electronic signal to the transmission and basically shift gears at will at the flip of a switch or press of a button. the idea almost sounds too good to be true but haven't found any source that could tell me it wasn't possible...

 

I don't think you could do it with just pushbuttons..... So far as I am aware, simply disconnecting the 8 pin connector would give you a pretty much manual trans. It is my understanding that it won't do ANYTHING 'automatic'...... You would just need switches, or some flavor of control for TCC, and O/D. (which are basically just energizing a solenoid.)

There are actually schematics for a control circuit for TCC and O/D online.... I think it uses a pressure switch, so it knows when the trans is actually in third gear. Not sure exactly how it works.... I didn't look that closely.

 

That's kinda the idea I'm going after is just raw control. I have a fair grasp of electronics and can produce rough gizmos as long as I can wrap my head around what needs to be done. Even if I have to make a few cleverly improvised switching circuits whether they be analogue or actual mechanical switches, so be it. But I mostly just need to know what form the commands from the PCM to the transmission will take. Hopefully somebody can come along and just give me a set of binary 12v on/off combinations for those 8 pins that I can use to rig together a rough manual tranny gear selector of some sort. I even have the tranny from the '99 5.9 project donor that I can use to experiment with, but I just need to know how the communication works.


​​​​​​apologies for kinda hijacking your thread by the way

 

Wiring diagram for the trans connector is in the service manual. You can download one from here. TCC, and O/D, are just solenoids. Complete the circuit to engage them.

 

The problem you might encounter there is that the sensors on the engine have 12v going in and are only signal voltages back to the pcm. The pcm then sends control signals to the transmission when necessary. They vary from .5v to 4.5v depending on the function of the sensor. It would be very difficult to mimic that. I think you're better off selling the 46re in favor of a 46rh.

 

Yes I'm familiar with the nature of the return signals from engine sensors to the ECM. in that plan I wouldn't be attempting by any means to home-brew any sort of device to emulate the sensor outputs, I would simply purchase after market sensors compatible with the carburetor conversion. The transmission control voltages are the only ones I would attempt to emulate and hijack in order to convert it to a semi-auto (clutchless manual) sort of setup