Update: I did find box for VR (thought I threw it away). Directions say to NOT polarize. Thank you for advice.

 

Polarizing went away when they changed from generators to alternators. You polarize a generator NOT an alternator.
Alternators came out in the early to mid 60s.

 

Why not head over to the bone yard and scarf up a used regulator or two. I'm pretty sure most will interchange. They rarely go out so this will get you on the road.

 

Update: it is in the late 30s today a little cold. I ended up buying a voltage regulator harness and plugging that into the regulator. When turning it over my multimeter dropped to 12.78 (at least it was not at 15.11V earlier implying the regulator was doing its job). Obviously that is too low so I went back to the repair place that fixed my fuel issues on the truck. He suggested running a ground cable from the regulator to the engine. I built one from 12-guage wire and put one loop on the one of the regulator screws and one on another screw on the engine. Turned over engine and nothing changed, still running around 12.78. Mechanic suggested if that failed to look at wiring from alternator to regulator. Battery is relatively new BTW (3/25) and fully charged when testing (multimeter read 13.1 normally, This morning after charging last night and plugging the battery in today I got three tests: Before putting the terminals on, after, and then after I attempted to start the truck (which slowly grinded and never sounded normal after hooking up a charged battery). Any ideas?

 

12.78 " when turning it over".
You mean while you're cranking it with the starter? If so that's actually pretty good.

 

I'm a little confused here. The voltage dropped to 12.78 when you cranked the starter? Anything above 11.0 volts is a strong battery when cranking the starter. If it's running 12.78 while the enigne is running, that's a charged battery and a little low. They usually run around 13.4 with the engine running and the battery charge restored.

 

You mentioned you had a battery drain, I posted a video on how to go about finding it. Did you find the drain?
How was the alternator tested? You can do a full field test without removing the alternator. This will show the maximum output. Then you can rule it out of the problem. I believe your truck has a shunt for the battery meter. These can fail, Dodge changed from the problematic amp gauge to a shunt style then abandon both for a regular volt gauge. I believe the shunt is between the battery and the alternator like the amp gauges were. So if it has an issue the alternator won't be able to charge the battery.
Your starter was grinding?

 

Charging voltage will vary on temp, load applied, battery state of charge, etc. newer cars with the charging system being totally computer controlled have a wider range of acceptable voltage.
Typically your truck while running can be anywhere from 13.3-14.8 and be "fine". Depends on these other things. There isn't a single one number in that range it "has to be".
I've had a couple over the years where I've had voltage much higher than that, and the battery was "cooking". Twice on my wrangler, and the battery was just shot. I could smell it and the battery gauge was "pegged" both times. A new battery solved it each time. I had that wrangler a couple of months short of 20 years. That one had a volt gauge in the factory dash. Our trucks have an amp gauge instead, which are both wired different. And a lot of these amp gauges didn't work 20 years ago... So there's that

 

Erm, I haven't seen an amp gauge in a vehicle for a couple decades, they are all uniformly voltage gauges. Some of the older stuff I have owned (60's and 70's) had an amp gauge, but, anything later than that? Nope.

 

Dodge went to a shunt system(80's) after using the hard wired amp gauges. Not sure what year they switched to a voltage gauge but my guess is when they went to throttle body injection.