I looked at the GM Heritage site and the "B" and "C" don't work as well as the 938475 for a production number. I suspect your suspicions may be correct regarding the California issue. Just to verify, these are stamped on the vehicle identification plate on the drivers door pillar, correct?

Ron - - Dusty53
1954 Chevy 3604
In the Gallery Forum
"You can't dance with the Devil and then wonder why you're still in Hell."
"They will forget what you've said, and they will forget what you have done but they will never forget the way you made them feel."