Rich, I am familiar with K10 having a 1980 myself, and I converted mine from an auto to a 4 speed, I think you mentioned using another transfer case and trans from another truck or different brand, kind of forget. I still have a good transfer case, and a bad auto sitting in the weeds, would certainly take a look to see if there was anything useful on it.
I was wondering how you made out with the Spicer hubs, mine had those, but had to be changed, when it was still on the road, I vaguely recall the parts diagram on these, was just wondering how that part of it went.
My ole K10, I replaced a motor with a rebuilt one, in 19 hours flat,( that was one long day) in early '91, then a few years later the auto went, I found a complete manual set up, pedals, trans/trans. case, cross member, was a low mileage rusted out earlier K series truck, for a few hundred, had the flywheel surfaced, new heavy duty clutch, still cannot believe I was able to do this job, mostly by myself, in one of the yards at work, best thing was the parts places and machine shop was nearby, great location to do the job, even if out side, couple of weekends it was done. The bad thing was I drove it out of NJ, up the NYS thruway, kinda just slapped some plates on it, got pulled over in NJ, talked my way out of it, she sits in my yard, what a great old truck, with that drive train I could knock trees over, just line them up with the plow frame, one thing is for sure, that truck may someday rust away, but I will keep that drive train for another. Mine has 270 gears in it, something was a bit off on the speedo when I put that 4 speed trans in it.