Ring Gear Spacer - 0.313 in Thick - Bolts - Steel - Black Oxide - 7.5 in - GM 10-Bolt - Kit

In General Motors (GM) 7.5-inch 10-bolt axles, there are two sizes of differential carriers: a 2 series (for gear ratios of 3.08 and lower) and a 3 series (for gear ratios 3.23 and higher). The spacer functions as an adapter so you do not have to buy a new carrier to change your gear ratio.