Mike - Can you tell us if it has a manual or automatic trans?
A quick peek on the web shows the '81 C70 primary manual transmissions would likely be an Eaton/Fuller 5 speed. The primary automatics I found listed for an '81 C70 are listed as an Allison MT640 or MT653.
I'd have to more digging to see what else I can find. The number listed for the transmission in your picture didn't come back with any listing I could find.
