My rig (a '74 FJ40) had a '74 "F" motor carb on the (transplanted) 2F engine when I bought it many years ago. The air filter was a small, circular K&N unit that *barely* fit over the top of the carb. So, smallish K&N air filters have been produced.
What is your issue with the stock 2F air filter housing? You can buy a K&N drop-in replacement air filter for this housing.
Another idea (which I though of doing some years ago but never did) is to construct an "under the hood snorkel" that moves the air intake from the carb to the far corner of the engine compartment and uses an open-air K&N element. I bought a K&N filter element (for a Mustang?) at a 4X4 swap meet as well as some PCV pipe to fab this up but never pursued the project.
I would think that an open element filter on a stock carb would be more problematic than helpful. The carb sits so far back in the engine compartment it gets splashed pretty good at every water crossing. The stock airbox offers decent protection from water, but an open filter would be asking for trouble, imo.