Any two piece horn from '66 up will work. It is the bracket that is different between the cars. One piece horns are usually specific to a car model.
First pic E Body two piece horn (removeable bracket)
Second pic '71 E Body one piece horn.
Third pic date codes, depending upon the horn the date codes may be in a different location.
Note the position of the bracket that attaches to the inner fender, also make sure you get a low and high note horn.
