I lucked out and found the parts for my transmission. It appears there is a tranny parts Internet company based here in Fort Myers. They sell used tranny parts and at a great price. I didn't think I'd find the parts for that 3L80 anywhere and if I did I was scared I'd get the whole tranny in the rear Bell first with no fluid if you know what I mean. The company is Sun State Transmission, AKA, Transmissionpartsusa.com. I ended up needing the direct driving hub from the forward clutch, the direct drive drum, the dish plate out of the direct drive clutch assembly and the center support. Got it all for $30.00. Not a bad deal in my eyes.
Well, I was up that entire night going through the gruelling process of cleaning every piece of the tranny. Crashed out around 6:30 in the morning, back up at 9:30 a.m. and finished reassembling the 3L80 slid it back under the van and put everything back together under there, filled it, started it, said a prayer and took off down the road. Amazing, what a difference, this poor van has never run so good. I did notice during the reassembly that someone had added a shift kit at some point and I was curious what effect it would have and I soon found out when it hit second gear and the tires chirped a little, nice. It's going on a week since I put it back together and all is well, so far. Still trying to get used to the extra power I have. If I don't pay attention to the speedometer, I find myself driving rather fast through the local streets or when I step on the gas it sets me back in my seat and making turns is going to take some getting used to. Keep in mind this is the largest van GMC makes (15 passengers), it's like driving a bus, literally.
This has been a great experience, besides the aggravation of being sold the wrong parts in the beginning (was sent the wrong torque converter, FYI, always check your new converter bolts to the old one before you reinstall the entire tranny) and tracking down the problem (procrastinating doesn't help). It wasn't nearly as scary as I anticipated or as complicated as it was made out to be, although being mechanically inclined and not knowing how to quit helps a little. I did learn that the dish ring in the direct drive assembly has a tendency to break and gather to one side creating an imbalance and wearing down hard parts of the tranny. I hope this helps someone someday.