Does anyone have decoding info on the codes which sometimes appeared beneath the paint codes on 1970 cowl tags? there is usually one or two letters followed by a sequence number. That number matches box 24 on a build sheet but I am particulalry interested in the two letter codes. I have seen a tag with two Bs and the only information I have been able to find is that they alerted assembly line workers to some non-standard item on the vehicle.

They are just plant specific codes and to assume they mean any special equipment or anything about the actual configuration of the car is mainly speculation.

There are more likely to refer to build operations rather the options. Also the plant where these show up are GMAD plants where other GM models besides Chevy were built and that could be what they refer to. But like all the rest I am just taking a WAG from years of observations.