What size truck will I need to tow a 28,000 pound trailer?

I tow a 23K RV with 5,800# pin that puts me at my RAWR of 9,750#. I could tow that weight no problem and it is rated to do so. BUT, if running a 25 percent pin as I do that goes out the window. Now with triple axle trailers the pin will be a lower percentage of the RV weight. Towing weight is all dependent on the RV's pin. My B&W puck hitch is rated 25K with 6,250 pin. I would have no issue towing higher with that hitch.