Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number D31 978 found under Liner Bearing Housing by Michell Bearings Member Of Rolls Roy. The National Stock Number assigned to this part is 3130012580868, and the Federal Supply Class is 3130 Bearings Mounted. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like D31 978.