C60S Transmission Question

[Grant Bowker]

Assuming that you are talking about the long thin, one - I found it easily at a local bearing supplier, current production.
I have also done business with www.obschevy.com or Tim Tygart's obsolete Chevy - your choice of names for them. Look specially at their NOS parts section. You have to search on part number, not a problem if you have the parts book. For example, they were able to source the early rubber covered gas pedal for the cab 13 (shared with some civil pattern) for me.