A potential problem with Super Sixing my 1973 Duster.

Dan, I do understand what you are saying about cutting the air cleaner/air horn ring. However, there is no light visible between the modified air cleaner hole and the air cleaner gasket when installed.

Decent effort at a test, but probably not good enough to squash the doubt.

the carburetor has stayed clean

This reminds me of when people say "I run my high beams all the time; I know it's fine because I don't get flashed". The one doesn't follow from the other. Likewise, a clean carburetor is a fine thing, but many kinds of dirt that can get in and brutalize your engine aren't going to make your carb look dirty.

I didn't like the look of the "Super Six" air cleaner housing especially on a 65 Valiant.

Me either, so I used a '66 318-2bbl air cleaner on my '65. That wasn't an option on the '62 (hood clearance).