As an update, I am now home, with the truck. We were able to located a Uhaul truck Monday morning to pull the trailer back to Slidell. Technically, the trailer is a 2 5/16" coupler, and the Uhaul had a welded-on 2" ball that we couldn't replace, so we pulled the trailer with too small of a ball. We loaded the Suburban as far forward on the trailer as possible to provide as much tougue weight as possible, and started towards Slidell. We made it home at 3:30am this morning in one piece. My cousin drove the car we picked up in Lubbock home with no plate or anything.
So far, we have not been able to take a moment to pull the tranny and determine the exact damage. My uncle and I theorize that the rear seal on the motor is shot, and has probably been run for a fairly long time with no oil, and that the tranny fluid pump is probably toast. The tranny fluid does not smell like burnt almonds, although none of us have/had great senses of smell. The fluid did not have a reddish tinge to it anymore. It wasn't brown persay, but the color was heading that direction. There is a fairly large quantity of some type of fluid on the front of the rearend and neighboring parts (my "back porch" lights, trailer hitch, transmission rear support brace, etc), but we haven't identified what type of fluid it is, presumably oil, but it doesn't seem to have an oily feel to it....the IMMENSE amounts of dust in Texas perhaps? The transmission is the last year 700R4 before they switched to the 4L60E, so no electronics on the tranny to worry about. My uncle looked on Phoenix Transmission's site, and it's looking like a new rebuilt transmission and torque converter is going to be about $1200 shipped with the 250 core charge. Depending on what we find out with the motor, a new crate motor may be in this truck's future too, if it'll be cheaper than rebuilding it.
I just got a call from my uncle. They pulled the truck off the trailer. To get the truck to roll backwards, he had to drop the driveshaft. So, apparently the tranny is so locked up, you can't even push/pull/drag it in neutral. We were able to pull/push it forward with little to no effort in neutral though. Sunday we will hopefully be pulling the tranny and making a damage report.
On a far-off side note....Sweetwater seems like a nice little town. Not much to do from what we saw, but we were somewhat preoccupied with other things..... I do appreciated everyone's willingness to help me when I was stuck out there. It sucks that noone was able to provide assistance, since I would have loved to have met all you fine individuals, but I made it home.