1978 GMC Pick-up Truck Differential Carrier K15 - 4WD - GM 8.5 in. - Yukon Grizzly Locker - 2.73 Gear Ratio And Up - 1.78 in. Bearing Journals - Uses LM102949/ LM102911 Carrier Bearings - Front guaranteed to replace your current 1978 GMC Pick-up Truck Differential Carrier K15 - 4WD - GM 8.5 in. - Yukon Grizzly Locker - 2.73 Gear Ratio And Up - 1.78 in. Bearing Journals - Uses LM102949/ LM102911 Carrier Bearings - Front. 1978 GMC Pick-up Truck Differential Carrier comes new OEM 1978 GMC Pick-up Truck Differential Carrier aftermarket new 1978 GMC Pick-up Truck Differential Carrier of remanufactured 1978 GMC Pick-up Truck Differential Carrier K15 - 4WD - GM 8.5 in. - Yukon Grizzly Locker - 2.73 Gear Ratio And Up - 1.78 in. Bearing Journals - Uses LM102949/ LM102911 Carrier Bearings - Front.