Repair,
There is actually no such thing as a 5-Speed Road Ranger. Does the shifter have an air shift button on the side?
Also wondering what year 9500 you have? Do you have any pictures of it?
I don't know anyone parting out an '80 C-70, but the best thing for large truck parts is to find a yard closest to your area. Calling some big truck parts stores in your area should get you some good recommendations for some big truck parts yards.
Bill