Revolution Gear Rear Axle Shaft for GM 8.5 Inch 1981-88 1500 4WD with 10-Bolt, fits both Left and Right side, 31.31 Inch 28 Spline (OE# 14039547 / Hollander# 447-1300). Revolution Gear replacement series axles are made from 1541H Steel and utilize computer controlled heat treatment processes.