I have been trying to ID what mirrors are on my '73. My screw center to center measurement is 3". This measurement matches the spacing on the nutserts in the door. I am assuming the doors are '73 doors. I have included pictures of the part number and date code on the base of the pass. mirror. I couldn't find the number in the 70-71,72,73 parts books. I also have a photo showing the length of the base (6 1/4"). Not sure if any of this info will help you. Any help anyone can give me would be appreciated.