1986 GMC Pick-up Truck Ring and Pinion Set C1500 - RWD - GM 8.5 & 8.6 in. - 10 Bolt - Ring and Pinion Set - 3.73 Ratio - Rear guaranteed to replace your current 1986 GMC Pick-up Truck Ring and Pinion Set C1500 - RWD - GM 8.5 & 8.6 in. - 10 Bolt - Ring and Pinion Set - 3.73 Ratio - Rear. 1986 GMC Pick-up Truck Ring and Pinion Set comes new OEM 1986 GMC Pick-up Truck Ring and Pinion Set aftermarket new 1986 GMC Pick-up Truck Ring and Pinion Set of remanufactured 1986 GMC Pick-up Truck Ring and Pinion Set C1500 - RWD - GM 8.5 & 8.6 in. - 10 Bolt - Ring and Pinion Set - 3.73 Ratio - Rear.