1997 GMC Pick-up Truck Differential Spool C2500 - GM 8.5 in. - w/ 10 Bolt Cover - 30 Spline - Spartan Locker - Installs into standard open carrier case - Rear guaranteed to replace your current 1997 GMC Pick-up Truck Differential Spool C2500 - GM 8.5 in. - w/ 10 Bolt Cover - 30 Spline - Spartan Locker - Installs into standard open carrier case - Rear. 1997 GMC Pick-up Truck Differential Spool comes new OEM 1997 GMC Pick-up Truck Differential Spool aftermarket new 1997 GMC Pick-up Truck Differential Spool of remanufactured 1997 GMC Pick-up Truck Differential Spool C2500 - GM 8.5 in. - w/ 10 Bolt Cover - 30 Spline - Spartan Locker - Installs into standard open carrier case - Rear.