It would handle it just fine. If it has air brakes, then you're even one more step ahead. I've loaded one up to almost 40k combined, and it was still ok. The 7.8 is a pretty good engine, just under appreciated. It would haul it better if you turn out the fuel screw. I pointed it out on my youtube video, and details are in the Low Buck Fuel Rate site(they dont let me post the link here).
commuter: 08 VW R32, or 67 F100,300,offy intake,edel carb,274* cam,header
Work truck:'94 IH 4900, DTA466 lightly bombed(#0 fuel plate, timing at 22*, 3 clicks tighter gov springs), Allison MT653, Voith retarder, and straight piped