Check your states trailer towing regulations and any other state that you are planning on trailering through. These trucks only had a GVWR and no max trailer weight rating so that depends on the state rules. If your lucky, the state will have the GVWR of just the truck on the scales and then the trailer weight rating on the scale... 10.000lbs for a K3500 Dually and then whatever the trailer is rated for on a separate weight ticket, could be 25,000lbs with working trailer brakes for a total of 35,000lbs for example. Other states have the trucks GVWR as the trailers max weight rating... 10k for the truck = 10k for the trailer even if its rated for 25k so the max would be 20k for that states regulations.
Just two examples but something to look into before you run 35k down the road.