[67L78Camaro]

Correct, the car does not have F41 suspension, just the standard big block SS parts, so it seems that the YG code tag is correct for the front springs. There are no indications prior to me going through the front suspension that the springs had been messed with, so I'm pretty sure they are the originals.

Perhaps while the spring part numbers might have been the same between Van Nuys and Norwood (which makes sense), maybe the Van Nuys plant had a different supplier for the tags, and that might explain the color difference.