i don't know if this is the only difference but 73 was the first year that had those two big bumper guards sticking out on each side so at least the mounting holes for those would be a difference.
i don't know if this is the only difference but 73 was the first year that had those two big bumper guards sticking out on each side so at least the mounting holes for those would be a difference.
different mounts completely , 2 bolt in 72 3 bolt in 73 & extended the bumper forward further not sure if any of the mounting holes would line up at all as they had a second bumper inside of the Chrome one