Anyone tow with a HDT? Going to buy our truck today and have been looking at the newer F450's. Will the F450 require bags to tow a mobile suite? I know trucks but I know nothing about diesels or HDT's. Would rather have the HDT to sit higher and all the benefits of pulling/stopping our rig but don't know anything about manufactures, milage, etc... We will be traveling rvers living full time. Thanks for any input.