I just bought this F350 dually 7.5 liter V8 to pull my 38' 5th wheel. It has only 135k miles on it and runs very smooth. Transmission shifts well, and seems to have no issues so far.
I only paid $3,500.00 dollars for this truck, but I got a lot of truck for the money. There are no rattles in the interior and no rust (Texas truck). Everything on this truck seems to be heavy duty, and feels like I'm driving an aircraft carrier. I love it when people get out of my way due to the size of this truck.
I've had several F-Series trucks, and all of them have served me well, as I'm sure this one will too.
The only thing I don't like is the gas mileage. Gets about 7 to 10 MPG. To be expected considering what this truck was designed to do.
The 7.5 FI V8 has more than enough power to pull just about anything! A lot of people brag about the 7.3 turbo diesel which is a great engine, however the 7.5 liter is a pulling monster. Nothing like big block power that needs no turbo! I would recommend any F350 with the 7.5 FI V8 or 7.3 turbo diesel for your pulling needs; both are great engines wrapped in a well proven truck. Just don't expect to pass any gas stations.