1977 Mercury Cougar Ring and Pinion Set Ford 9 in. - Ring and Pinion Set - 4.56 Ratio - 9310 Pro Gear - Oversized 35 Spline Pinion - Rear guaranteed to replace your current 1977 Mercury Cougar Ring and Pinion Set Ford 9 in. - Ring and Pinion Set - 4.56 Ratio - 9310 Pro Gear - Oversized 35 Spline Pinion - Rear. 1977 Mercury Cougar Ring and Pinion Set comes new OEM 1977 Mercury Cougar Ring and Pinion Set aftermarket new 1977 Mercury Cougar Ring and Pinion Set of remanufactured 1977 Mercury Cougar Ring and Pinion Set Ford 9 in. - Ring and Pinion Set - 4.56 Ratio - 9310 Pro Gear - Oversized 35 Spline Pinion - Rear.