I've got my dd sitting about 625-650 at the rear wheels I pull my 32 ft toy hauler loaded with fourwheelers, choppers or whatever else were playing with for the weekend I pull every single weekend and sometimes during the week picking up backhoes and materials for a job site, haven't had a single issue with my set up and I run level 3 on my DI tune at all times, if you drive normal and use the power right and not trying to drag race (even though the faces on people are great when you pass them up doing 95 down the highway) with a load then there shouldn't be any problem if it's done right