Iím a VW guy but my brother has a 68 Ford I get to work on, I was unimpressed with a lot of the hardware in the V8 world one that I had to make was a nice air cleaner wing nut. When it comes to air cleaner wing nuts you will find Taiwan made cast junk.
These wing nuts are made in house in small batches from 6061T-6 they have the standard ľ-20 thread, and have a anti scratching O-ring so it will not scratch your air cleaner. Base is 1inch diameter. Have something that everyone else at the show will not.