Okay now I'm confused. You said it would be three numbers and then you give me an example with a letter and two numbers. Valiants and Barracudas are different? It's random?
First digit, month
1-9 Jan-Sep
A-C Oct-Dec
Last 2 digits are the date
This is the same for all plants during this era (60s/70s).
All cars, all plants
Even at a plant that makes different cars
VIN might look something like this at a plant
BH29D72100001
BH23D72100002
VL41B72100003
BH23E72100004
etc.
A different plant would start at 100001 as well
Back to my example
BH29 Car-line/Body-type
31 - Engine
5 - Transmission
235 - Tires
B29 - Date
02016 - Shipping/Sales Order
The codes above this are the different options.