To jeffw:
I'm new to this stuff too, but know several good suppliers of old Chevy truck parts. Since your thread is about two years old, you probably already have this information, but here it is.

chevsofthe40s.com
fillingstation.com
oldchevytrucks.com (Jim Carter)
lmctruck.com
brotherstrucks.com

If these guys don't have it, it might not be available.
If you know of others, please let me know.

OldRustyWrench52 (Dave)