1999 GMC Sierra Differential Carrier Sierra 2500 - 4WD - Yukon Dura Grip Positraction - GM 10.5 in. / 14T Rear - 14 Bolt Cover - 30 Spline - 4.10 And Down or Thick Gears - Rear guaranteed to replace your current 1999 GMC Sierra Differential Carrier Sierra 2500 - 4WD - Yukon Dura Grip Positraction - GM 10.5 in. / 14T Rear - 14 Bolt Cover - 30 Spline - 4.10 And Down or Thick Gears - Rear. 1999 GMC Sierra Differential Carrier comes new OEM 1999 GMC Sierra Differential Carrier aftermarket new 1999 GMC Sierra Differential Carrier of remanufactured 1999 GMC Sierra Differential Carrier Sierra 2500 - 4WD - Yukon Dura Grip Positraction - GM 10.5 in. / 14T Rear - 14 Bolt Cover - 30 Spline - 4.10 And Down or Thick Gears - Rear.