My air cleaner has a little knurled nut on it that has a little more reach than a wing nut. It has a narrow part that goes in the hole. Not sure if it's stock, though. It was like that when I got it.
You might replace the threaded rod with a slightly longer one.
1950 Chevrolet 3100 (Ol' Roy)
1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)