Thanks Nomadic. The transfer case was swapped out last Friday. I flew back to Butte Friday night and set out again Saturday morning. On my first walk around I noticed the air cylinder on the rebuilt case has a leak. At the forward end, around where the "end cap" bolts to the cylinder, not at a hose connection. It wasn't too bad and the compressor seemed to build and maintain pressure (and cycle on and off normally) so I kept going and kept checking it. As long as it didn't get worse, I knew it would be ok for a day or two. Probably an easy fix once I'm home.
I drove for about 12 hours and pulled into a truck stop to refuel and rest for the night, but I was only just over 100 miles from home. It was raining pretty hard but I decided to keep going. I'm glad I did.
I ended up doing the Butte, Montana to Seattle stretch in about 15 hours. Not too fast but I was happy to finally get home and sleep in my own bed.
It was an adventure and a learning experience.
The next day I found the exhaust stack is breaking off the muffler. The tube that extends from the muffler to the flange where the stack bolts on is just "tearing off". I'll have to weld it up. Not a big deal, but glad it held together enough to get home without it flopping around and leaking exhaust up into the cab. I clamped it together for now.
Once this thing's parked in it's "long term" spot. There's no pressure on me to do anything. I'll play with it next summer when I feel like it. Maybe I'll keep it for 20 years, maybe I'll sell it (fresh transfer case!) but I'll never have to wonder what it feels like to drive a big, old class 8 truck cross country!