Wow, a lot of information in no time at all. Thanks everyone for all the facts and opinions. I seem to have an ailment that only allows me to buy the largest version of everything I buy. My guy genes wants the big rig tow vehicle, but I really need to stay with the smaller truck. Two bad knees make climbing in and out of the big rig a challenge that I can mange now, but will likely be a problem down the road when I get my freedom and can really use the rig. I think the F-350/450, 3500/4500 may be the right way to go. I pulled one this size and approximate weight in the past with a Dodge 3500 and was impressed with how well it pulled, just not a big Dodge fan. I guess it is time to go shopping. Does anyone have any suggestions on manual vs automatic transmissions? I know in my Ford the tranny is the weakest link, and I have heard the same about Dodge. The Allison is a great transmission but you would have to come out of retirement to rebuild one if it failed. I have been thinking about buying a manual behind a diesel, but was wondering if there are problems associated with pulling a rig this big/ heavy.