2022 PACCAR MX13, Truck Tractor, Engine Assys, Fits to: Peterbilt 579, (Used) 2021 PACCAR MX13, ENGINE ASSEMBLY- Family Number: MPCRH12.9M21, Displacement: 12.9L, Horsepower: 340/456, Serial Number: Y265499, Part Number: 2272653, E.C.S.: CAC, ECM, EGR-C, OC, SCR-U, PTOX, AMOX, For more information about this item, give us a call. We ship Worldwide! (CRG HEAVY TRUCK PARTS) 929 W PULASKI HWY, ELKTON, MD 21921, Horse Power 340/456, Serial# Y265499, Casting# Y265499 1XPBDP9X9ND707991