Need 208 Transfer Case Help

[hotrodmtodd]

Guys,
I REALLY need some help here. I borrowed a friends '86 K-20 to bring my '68 Burb home to PA from MD. About half way home I realized that it was going to be TOO MUCH of a strain on his truck to try to drag that heavy Burb up and down the mountains on I-68, so I dropped it off at a gas station and went back on the weekend to pick it up with a BIG truck and trailer. BUT, I got his truck NEARLY home and wound up having to put a $673 TH-400 in it for him. 2 days later, the transfer case went south, so I bought an '85 Blazer with a 208 in it and gave it to him to help him out. The tranny shop failed to mention that there is a C-1 for TH-400 and a C-2 for 700R4. (I think I got that right) Anyways, what I need to know is, do you HAVE to use one for one, and one for the other, or can you swap parts from one to the other to make it work? I am starting to have more invested in my friends truck than in MY OWN. I have a tendency to ALWAYS do the right thing by people, so I want to make it right for him, but I need the help of the experts to get it done. I regret that I have been a 2WD guy for most of my 42 years, so I hope you guys can set me straight on this. Can I swap in a different T-case instead of the 208? Please help me get him back on the road with the least amount of problems. Thank you, Mike