The 2015 Ford F-350 Crew Cab 4×4 Dually has an upgraded V8 turbo-diesel Power Stroke engine. The bigger turbocharger and updated injectors combine to make 440 horsepower and 860 lb-ft of torque at 1,600 rpm. So, how does it do when towing a 1942 M2 Halftrack (combined weight with trailer 21,600 lbs) up a steep incline at over 11,000 feet of elevation? How does it compare to the Ram 3500 with the same trailer?