Part Notes: 4 Wheel Drive, 3.73 Ratio, Without Anti-Spin, 3500;4 Wheel Drive, With 11.5 Axle, Without Anti-Spin, Without Dual Rear Wheels, 3.73 Ratio;Mega Cab, 4 Wheel Drive, 3.73 Ratio, Without Anti-Spin, 3500;Regular/Quad Cab, 4 Wheel Drive, With 11.5 Axle, Without Anti-Spin, Without Dual Rear Wheels, 3.73 Ratio