Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 21-74S found under Float Carburetor by Acf Industries Inc. The National Stock Number assigned to this part is 2910003608003, and the Federal Supply Class is 2910 Engine Fuel System Components Nonaircraft. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 21-74S.