I dont know about a shortbed, but my longbed C-20 has 350/700r4 and I took the stock driveshaft to get shortened at a shop. Mine is a 2 piece driveshaft and I had one cut and rebalanced(dont remember which one was cut, shorter or longer one) and they installed a new carrier bearing. The tranny was a TH350 and the splines are the same.
I am interested to see if any other years would work just to learn something today
