1978 GMC Pick-up Truck Ring and Pinion Set C25 - RWD - GM 10.5 in Rear - w/ 14 Bolt Cover - 4.56 Ratio - Ring and Pinion Set - Fits 4 series 4.56 & Up Carrier - Rear guaranteed to replace your current 1978 GMC Pick-up Truck Ring and Pinion Set C25 - RWD - GM 10.5 in Rear - w/ 14 Bolt Cover - 4.56 Ratio - Ring and Pinion Set - Fits 4 series 4.56 & Up Carrier - Rear. 1978 GMC Pick-up Truck Ring and Pinion Set comes new OEM 1978 GMC Pick-up Truck Ring and Pinion Set aftermarket new 1978 GMC Pick-up Truck Ring and Pinion Set of remanufactured 1978 GMC Pick-up Truck Ring and Pinion Set C25 - RWD - GM 10.5 in Rear - w/ 14 Bolt Cover - 4.56 Ratio - Ring and Pinion Set - Fits 4 series 4.56 & Up Carrier - Rear.