Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 74604-903 found under Piston Hydraulic Motor Pump by Spencer Industries Inc. The National Stock Number assigned to this part is 4320013078864, and the Federal Supply Class is 4320 Power And Hand Pumps. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 74604-903.