2004 Mack AC 427, Truck Tractor, Engine Cores, Fits to: Mack CH613, (Used) 2003 MACK COMPLETE ENGINE ASSEMBLY, Model: AC 427, Horsepower: 427, Serial Number: 3M1831, Engine Family: 3MKXH11.9H64, Displacement: 11.9L, For more information about this item, give us a call. We ship Worldwide! (CRG HEAVY TRUCK PARTS) - ARR/CPL: Other, Horse Power 427, Serial# 3M1831, Casting# 3M1831 1M1AA18YX4N156170