kb3csw,
I am as unclear as you and I posted the darn info! I facilitated the deal with the derating of the truck, and I know how it was accomplished, with the tires etc, but now I'm not sure why we did it! I might have been mistaken and it was to bring the GVW down to circumvent the need for a class A license which would require the yearly physical. The truck was derated but still has the air brakes. I am it's only driver now and I don't have a commercial license. I have been stopped by the CHP and they were not concerned about the class of my license.

Stuart.