[valiant67]

Not all of these cars changed to a steel bumper. The aluminum bumper continued to be used after 1979 and through 1981. Steel bumpers were more common on the fleet cars. The 1980 parts book shows a steel and aluminum bumper for the lower line cars (St. Regis, Gran Fury and Newport) but does not show an option in bumper materials and remained aluminum for the New Yorker. I don't have a 1981 parts book, but I had a 1981 New Yorker and it still had aluminum bumpers. Newport used a different bumper than New Yorker. I think there's a good chance steel bumpers don't exist for your car, but maybe they do.