As TurboIndian said I have not had a problem pulling a load and mine is 100% stock. My 7.3 had a little more grunt in the first 10 to 20 feet but then it is all over. The new Dodge 600 in stock form my friend has can not keep up with me going up black Mt. pulling our boats, and my boat is much bigger than his and I have a crew cab and he has the extended cab. But when mods are added it will be a different story and I will be seeing the prop on his Honda 4-stroke. The cummings is just eaiser to mod but you still have a Dodge truck to put up with. I have heard that the Dodge truck is getting better though. The reason I went with the Ford is the solid front axle (D60),the room of the crew cab, and the Ford just looks better to me. I have had 25 Ford companey trucks over the years and all with 100,000 miles+ and never put one into the shop for a problem. I am glad I don't have to buy a new truck at this time with all the changes that are going on.
Good luck,
Jim