10-31-2009, 05:57 AM
The most noticeable external change to the 1973 Mustang was the addition of a high-impact molded urethane front bumper, required to meet 1973 federal safety standards. This larger bumper sits somewhat lower than the previous year models, requiring a smaller bumper notch in the fender. A quick and easy way to tell the difference is to look at the top of the bumper notch in relation to the marker light opening. If the top of this notch is even with the top of the marker light opening, it's a '73 fender. If a line extended from the top of the bumper notch is noticeably above the marker light opening, it's a '71-2 fender.