1981 Dodge Pick-up Truck Ring and Pinion Set W150 - 4WD - Chrysler 9.25 in. Rear - Ring and Pinion Set - 3.90 Ratio - 29 Spline Pinion - Rear guaranteed to replace your current 1981 Dodge Pick-up Truck Ring and Pinion Set W150 - 4WD - Chrysler 9.25 in. Rear - Ring and Pinion Set - 3.90 Ratio - 29 Spline Pinion - Rear. 1981 Dodge Pick-up Truck Ring and Pinion Set comes new OEM 1981 Dodge Pick-up Truck Ring and Pinion Set aftermarket new 1981 Dodge Pick-up Truck Ring and Pinion Set of remanufactured 1981 Dodge Pick-up Truck Ring and Pinion Set W150 - 4WD - Chrysler 9.25 in. Rear - Ring and Pinion Set - 3.90 Ratio - 29 Spline Pinion - Rear.