The front mount for a '60 - '62 C10 - C40 is 3763767, Filling Station lists 70-1828 (rebonded 37363767), as do some others. The mount fits to the timing plate on 6 cyl or to the horse shoe bracket on a V8.
I found a NOS 3763767 mount a few weeks ago off Flee Bay for $95, searched for some time so I'm glad I scored it. Have it in hand, looks good.
