Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 5B3-1 found under Disk Clutch Vehicular by Motor Coach Industries Inc. The National Stock Number assigned to this part is 2520010227960, and the Federal Supply Class is 2520 Vehicular Power Transmission Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 5B3-1.