Dave:
The cabs are the same until you get to the bottom of the rocker panels. The big bolts have a rocker extension that infills the area between the bottom of the rocker to the top of the factory running boards. It is not a direct bolt-on. Additionally, the big bolt fenders have flares, as well as extensions on the cab corners. You may be better off fabricating something, otherwise you will need the extensions for the fenders, rockers and corners. Also, the frame rails on the big bolts are lower, thus the running boards mount directly to them.
Good luck with the retrofit.
Tony
PS - Have you done anything to the C30 since I saw it a few weeks ago?
