Use the more readily available 4bbl. air cleaner on a Rochester 2bbl. carburetor. Accessorize with aftermarket air cleaner and retain stock 2bbl. carburetor and intake. Racing classes using a 2bbl. can benefit from the higher flow of a 4bbl. air cleaner. Made of high strength ABS plastic. Adapter has a 3" I.D. and a 5-1/8" O.D.