1978 Pontiac Grand Prix Differential Carrier RWD - Yukon Dura Grip Positraction / Limited Slip - GM 8.5 in. Rear - 28 Spline - 2.73 And Up - 1.781 in. Bearing Journal - Rear guaranteed to replace your current 1978 Pontiac Grand Prix Differential Carrier RWD - Yukon Dura Grip Positraction / Limited Slip - GM 8.5 in. Rear - 28 Spline - 2.73 And Up - 1.781 in. Bearing Journal - Rear. 1978 Pontiac Grand Prix Differential Carrier comes new OEM 1978 Pontiac Grand Prix Differential Carrier aftermarket new 1978 Pontiac Grand Prix Differential Carrier of remanufactured 1978 Pontiac Grand Prix Differential Carrier RWD - Yukon Dura Grip Positraction / Limited Slip - GM 8.5 in. Rear - 28 Spline - 2.73 And Up - 1.781 in. Bearing Journal - Rear.