Can someone explain what the -28 means that is commonly written in grease pencil on the radiator shroud of restored Camaros, if it is a number from a factory test wouldn't it very from the commonly seen -28 from car to car? and is this something judges look for in a concourse restoration? Since I am just finishing a four year restoration which I want the car to be as accurate as GM off the line without the over-restored graffiti.
