Please remember what I said. IF the PO installed springs to achieve the lift it is highly likely the springs are no longer rated to handle the load. Most lifts use really soft springs to achieve a soft ride off road where lifts are suppose to work. The OP needs to research the lift and try to determine thespring load rates before he attempts to tow this trailer.
BTW the GD web site lists the trailer as a 11,995 GVWR and 9900 pounds dry.
Remember the truck is no longer stock, so ALL factory numbers and specs are out the window.
