Air filter recommendation

The filters of equal size, paper vs. a K&N, the paper will out flow it when new. The draw of the K&N is constant steady flow on a reusable filter element. If you can use a slightly taller filter for more filtration area, go for it.

On the filter you describe, a 14x3 w/a filtered lid I have run for years and find it good.

Get rid of the drop base if you don’t need it. Get a flat bottom that has a slightly higher base than the carbs opening. Most factory air cleaners have a base like this with a good shape into the carb.

Seal the carb to the hood to reduce heat and or all under hood debris like burning oil from small leaks, rocks from the road, etc...