Hey Tim, I just replaced my front cab mounts yesterday. My kit was the same as yours and I think they are short two rubber shims. My truck originally had a rubber shim between the cab and the frame to isolate vibration, and then it had a shim between the frame and the square washer. I reused two of my old rubber shims to have the correct number. I cannot believe the improvement in road noise. You will want this bottom washer to prevent noise from traveling up the cab mount bolt into your floor board. The rear shackle mount has nothing between it and the cab.
