1973 duster door tag sticker

The SPD on the fender tag doesn't always match the door sticker. My Challenger's SPD is 927.(September 27th) The door sticker says October 1972 on it. The car was built two weeks later then the SPD.

Also, the VIN stickers changed in late 72 for E-bodies....maybe A-bodies too. An MDH(month/day/hour) code was placed in the lower left had corner of the sticker. There will be no way to know the code unless you can look at the original sticker.