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Pulling/towing is a question of torque produced by the engine and gear ratio. Which engine type produce the highest torque? Diesel does. yes you can put a 5.7 Hemi or a 6 liter gasoline engine in a truck with a low final gear ratio and they'll pull anything is it efficient? NO a strong gasoline uses mor gas than a smaller diesel with the same torque.
I recommend like Garris and some others did a (just run in) diesel with >100K miles on it with the cab arrangement you'll like for daily driving.