There's a slight difference between the 71 and 72 GTO hood, but from the outside there's no difference. On the leading edge of the hood (underneath), about 4" to either side of center, the 72 hood has indentations about 3" long. You can't see it with the hood down, but very obvious when the hood is open. Again, it's a minor thing, but without checking the code, it's an easy visual way to to tell the difference between a 71 and a 72 hood.
