Okay...i have to...
Dodge.
You can't go wrong with a dodge. Dodge Ram 3500 has the cummins engine, 6-speed manual (or automatic bleh) has never failed me.
Ford F350 with a powerstroke....good but last time I drove my friends automatic the transmission crapped out going 70mph on the freeway pulling a 4 horse slant (fully loaded).....
Ford really can't compare to dodge for towing
Just saying...dodge.