Well I certainly never knew there was a difference. Last week I had the original owner over to see the car and he told me that he had to replace the air cleaner in '71 after someone accidentally ran over his. The next thing that happened was a Mopar expert from the area was over to lend me a torsion bar tool, took one look at the air cleaner and said "that's a '71 air cleaner". So now I'm confused. Here are two pics of it:
