[dsraven]

Check the integrity of the metal around the cab mounts as well.
I believe that if the frame is level then the cab step would also be level. I use a digital torpedo level for this and if a longer run is nedded, like across grame rails maybe, I use a longer level with the digital level sitting on top. Digital is gonna give the same reading no matter what angle you look at it. A bubble level should be looked at from directly in front for a more accurate reading. Some are simply "close" no matter how you look at it.