1999 Isuzu Other, Truck Delivery, Complete Axle-Front Rears, Fits to: GMC W4, (Used) 1999 Gmc W4, COMPLETE REAR DIFFERENTIAL- Make: Isuzu, Model: R040, Ratio: 5.125, Capacity: 11,020 Lbs, Hub Bolts: 6, Brake Type: Hydraulic Disk, For more information about this item, give us a call. We ship Worldwide! (CRG HEAVY TRUCK PARTS) 929 W PULASKI HWY, ELKTON, MD 21921, Ratio 5.125, Serial# TBD, Casting# TBD 4KDB4B1R0XJ000246