Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 21840F78-11.75L found under Gear Assembly Speed by Cleveland Gear Company Inc. The National Stock Number assigned to this part is 3010014726976, and the Federal Supply Class is 3010 Torque Converters And Speed Changers. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 21840F78-11.75L.