Is it BO and LO or is it B0 and L0….that is the question??

I have a related question regarding the super stock 68 Barracudas. I understand that the VIN plate for all 68 Barracudas was located on the dash assembly on the base of the windshield on the driver's side. the VIN numbers ONLY also are stamped on the radiator support frame and on the rear trunk lip under the rubber weather strip on the driver's side. does anyone know what it would mean if a car had stamped on the radiator support frame "B0" and then the six number VIN? did the super stock cars have the B0 stamped on the radiator support?