Has anybody done some heavy duty towing with thier Titan yet? I know the CC (with the towing package) has a 9400 lb towing capacity but I haven't read where anybody has towed anything near that heavy. I'll be hauling around 8000 lb's, with about 600 lbs toungue weight, (boat and tailer) up and down some steep grades pretty often during the summer. I have preveously towed my boat with a F250 HD. I just don't want to beat the crap out of my new Titan on order for April delivery.