Revolution Gear and Axle, Replacement series, Rear axle shaft for GM 8.2 and 8.5 Inch 68-72 Chevelle and El Camino, 70-81 Camaro, fits both Left and Right side 30.13 Inch 28 Spline (OE#1255802 / Hollander# 447-1015). Revolution replacement series axles are made from 1541H Steel and utilize a state of the art computer controlled heat treated process. The use of better material and better heat treating process gives our replacement axles a 10 Percent increase over the OEM axles.