We just brought home a new Landmark Newport and I think I am way over capacity with a 2012- 3500 SRW Ram. Dealer says your fine but I don't think so. 18000 GVW is dually capacity to my thinking after towing it home in a stiff headwind. How do I tell the other half we need a Max tow 3500 DRW Ram. No interest in other brands whatsoever.