On paper either one of those trucks should be able to handle a 7800 GVWR trailer when properly equipped. Unfortunately not all 7800 lb trailers are created equal and there are certain characteristics that will make one tow well and another a real turd. Trailers with high yaw inertia will have a tendency to sway more even with proper CG location. Stay away from front/rear kitchen layouts, front and/or rear slideout positions, central located axle positions, unknown tire manufactures. Floor plans with heavy items such as slide outs, kitchen, and fresh water tanks centralized close to the axles and loaded correctly will tow better. Everyone on these forums are so hung up on payload rating now days it’s ridiculous. Having adequate payload is required but it does not guarantee towing stability in anyway. I rarely see anyone mention anything but hitch weight when it comes to trailer stability but there’s much more to consider.