Air cleaner for 2 1/4" carburetors. Typical standard USA 1 barrel. The air filter is cleanable and resuable. Can use the K&N air cleaner oil. These are high quality air cleaners that mount directly on the straight side, clamp style air horns. They can be used on a center stud mount type by drilling a 1/4" hole in the center.
Clean and re-oil at 20,000 - 30,000 miles, depending on dust conditions.
Fits most Holley 1904, Rochester B