67 s code GTA FB April 67 San Jose, markings on inner wheel well right side upper I'm guessing other cars would have this mark what did it exactly mean if anything
For others these are fairly specific to plant and year so please don't copy these to other cars or periods.
Because your car was/is a 390 car there are workers who needed a visual clue from a distance that it was so a worker applied the "S" to indicate this. This is one of three possible locations of this mark. Location depended on which of the shifts your car was build during and in turn the shift the worker assigned to applying this mark.
The "D" is a commonly found mark found on San Jose cars through out the years. Not sure what it relates to or indicates. None of the workers I've talked to used or applied it so they had nothing to offer. It can normally be found in one of three locations depending on time period. Not related to engine, transmission, brakes or anything else as far as options or equipment that I could find
