(Used) GM/Chev (HD) 6.0L, ENGINE ECM- ECM Model: E78, Part Number: 12686539, Serial Number: 86ACD5K28047EMNG, Serv. Number: 12668991, 1 Rectangular Plug with 55 Pins, 1 Rectangular Plug with 73 Pins, 1 Rectangular Plug with 65 Pins, Reference images for condition. For more information about this item, give us a call. We ship Worldwide! (CRG HEAVY TRUCK PARTS) 929 W PULASKI HWY, ELKTON, MD 21921