He bought a Ford as the truck for the task. F250 Diesel. About every option available except dually rear end. He burned up 2 transmissions in 110,000 miles though the engine never missed a beat.
So he bought a Dodge Cummins diesel, and he's never had any trouble with this truck. He and my mom have it on the road at least once a month, so they are using it often to tow heavy loads.
Like a poster said, he may have the entire truck go south on him before the diesel engine give up. That might be true of lots of diesel trucks, though.
My fiancee’ has a custom Dodge 2500 diesel with a Cummins engine, 4x4 and 6 sp manual tranny. He has had no major malfunctions with it. He did have to replace the clutch recently but he just did it himself.