Ford Racing ring and pinion sets are engineered, manufactured, and tested for maximum performance. These ring and pinion sets are finished in a black oxide coating for corrosion resistance, and are available in many different ratios to fit a variety of Ford differentials. Ring Gear And Pinion Set; Fits 8.8 in. 10 Bolt; Rear; 3.31 Gear Ratio; 8.8 in. Ring Gear Dia.;