This may have been asked and answered already and if so I appoligize in advance... I just purchased a 2005 Cummins TD 2500 that came with the factory installed towing package including the 7 pin round electrical conection and hitch receiver. However, I was ready to order a new drop hitch ball mount and since I have the truck at our house out of state I can't measure the receiver. Does anyone know whether it is a 2-1/2" square or 2" square receiver? I would think with this truck's capacity it would be the larger but I'm just not sure. Anybody know?