Chromoly Inner Front For Dana 30 27 Spline Left Hand 18.8 Long D30 JK '12&Up 27 Spline Left Hand Inner 18.8 Inch Uses 1350 U/Joint 4340 Yukon Gear & AxleYukon high performance axles are built with high strength 4340 chromoly, use superior production methods that include cold roll formed splines, and feature induction coil heat treating to create an axle of unmatched quality and durability. Yukon high performance axles are built with high tensile strength 4340 chromoly, use superior production methods that include cold roll formed splines, and feature advanced induction coil heat treating to create an