The production numbers of series/models as well as options are taken from Chevrolet's published reports. If someone comes along and says, "Well, it's 1 of 25 blue (pick a color) sport sedans, or 1 of 25 with this engine/transmission combo..." they're blowing smoke. Chevrolet did not keep track of any combinations of options, only individual options. Color numbers were not published until the 1975 model year.