1947 Plymouth Numbers

Where are the "Secret" numbers stamped on 1947 Plymouths?
If indeed there are any?

 

It's a secret.

 

There should be an engine# stamped into the driver side frame rail over the rear end. The rest of the numbers are in plain sight on tags riveted to the body or stamped into the engine.

Engine# : just above the generator
Body# : riveted to the firewall above the steering column area
Serial# : riveted to the driver side door jamb by the upper hinge