Ring & Pinion Replacement Set For Dana 30 In A 4.27 Ratio USA Standard GearUSA Standard Ring and Pinion replacement gear set for Dana 30 inch a 4. 27 ratio. USA Standard ring and pinion sets are the right choice to add confidence to your install. USA Standard Gear offers a full line of ring and pinion sets for a variety of common and hard to find applications. USA standard gear offers a standard one year warranty against defects on their ring and pinion sets Features and Benefits: All USA Standard Ring and Pinion Gear Sets