On the left is a high-pinion Dana 60 ring-and-pinion. A True Hi9 ring-and-pinion is on the right. Both gearsets are 4.88s. The True Hi9 has a thicker ring gear, a larger pinion head, and the third bearing on the pinion. The only advantage of the Dana 60 is the 29-spline instead of 28-spline pinion stem.