1991 GMC Pick-up Truck Differential Rebuild Kit K3500 - Dana 70 HD Rear - Differential Rebuild Kit - Koyo Bearings - w/ HM807010/ HM807040 Inner Pinion Bearing (4.125 in. OD Race) - 453X/ 469 Carrier Bearing & Race - Rear guaranteed to replace your current 1991 GMC Pick-up Truck Differential Rebuild Kit K3500 - Dana 70 HD Rear - Differential Rebuild Kit - Koyo Bearings - w/ HM807010/ HM807040 Inner Pinion Bearing (4.125 in. OD Race) - 453X/ 469 Carrier Bearing & Race - Rear. 1991 GMC Pick-up Truck Differential Rebuild Kit comes new OEM 1991 GMC Pick-up Truck Differential Rebuild Kit aftermarket new 1991 GMC Pick-up Truck Differential Rebuild Kit of remanufactured 1991 GMC Pick-up Truck Differential Rebuild Kit K3500 - Dana 70 HD Rear - Differential Rebuild Kit - Koyo Bearings - w/ HM807010/ HM807040 Inner Pinion Bearing (4.125 in. OD Race) - 453X/ 469 Carrier Bearing & Race - Rear.