How much air psi do you have in the rear tires? if at 80, lower it to 40 or so lbs, that will make the ride somewhat nicer. Also shocks could be an issue too.
Those would be the first two things I would look at! Its also possible, the new one has a MUCH stiffer and stronger suspension than your old one, IE old was 8500 lbs of rear spring, new is 9500-10K lbs of spring rating! along with increased tire capacity etc, so it WILL or SHOULD/COULD potentially ride rougher. Now with that, my navistar with a 15.5K rear suspension is not too bad...then again, I have a spring suspension seat too.......
marty
