I came across a Hot Rod shop this past weekend, that was doing some restoration work on a AAR (the guy is a flipper) and I thought something looked out of place on the car.

It had the 70 'cuda rocker gills.

I'd never seen a AAR with gills on it - I thought they only came on regular 'cudas. After looking through pics on this site, as well as on the AAR registry, it seems to be rare, but some AAR's do have them.

What's the story on those? Was that something that Ma Mopar randomly bolted onto AAR's, or do some owners just like the looks of them and add them to their cars?

The only AARs that had them were the pre-production ones. They were not used on production cars.

Thanks, that's kinda what I thought.

More likely owner's installed them because they like the looks. You see them on a lot of clones too.