Looks like cargo payload is going to be a problem, so a TT may be the only way for us to go. I don't mind beefing up the suspension but that will only get me about 1,000 pounds extra cargo payload and the is still pushing the limits. So we will keep looking for now.
As for driving 65-70 mph, that was a test just to see what the truck would do going up the Grape Vine. I normal drive a 60 mph when towing. Though the truck wants to go faster if I don't keep an eye on the speedometer.
Still curious about which unit has more wind drag, a TT or a 5th wheel? I am thinking the TT has more wing drag as Ram states the truck can pull 4,000 pounds weight in a 5th wheel than a TT. Being that wing drag is equal to added weight but I could be wrong.
Thanks again,
Craig