A friend of mine has offered to give me a new rechromed 72 rear bumper to go on my 71, which I like the 72 bumpers better anyway. He has offered me the whole setup, lenses, wiring harness, brackets and all. I know they are different, but are they interchangeable? Will the valance line up? Will the bolt holes for the brackets line up? I'd like to know before I go yanking my bumper off of mine and trying it.