1972 GMC Pick-up Truck Ring and Pinion Set K25/K2500 Pickup - GM 10.5 in Rear - w/ 14 Bolt Cover - 3.73 Ratio - Ring and Pinion Set - Fits 3 series 4.10 & Down Carrier - Rear guaranteed to replace your current 1972 GMC Pick-up Truck Ring and Pinion Set K25/K2500 Pickup - GM 10.5 in Rear - w/ 14 Bolt Cover - 3.73 Ratio - Ring and Pinion Set - Fits 3 series 4.10 & Down Carrier - Rear. 1972 GMC Pick-up Truck Ring and Pinion Set comes new OEM 1972 GMC Pick-up Truck Ring and Pinion Set aftermarket new 1972 GMC Pick-up Truck Ring and Pinion Set of remanufactured 1972 GMC Pick-up Truck Ring and Pinion Set K25/K2500 Pickup - GM 10.5 in Rear - w/ 14 Bolt Cover - 3.73 Ratio - Ring and Pinion Set - Fits 3 series 4.10 & Down Carrier - Rear.