I don't think that RAM would put on tires that couldn't handle the towing capacity of the truck. I tow about 4500 lbs regularly and would tow up to 10,000 lobs without thinking about it. It isn't like your tires are taking the entire 7,000 lbs - it is being distributed through your trailer and trailer tires. I would think that as long as your tongue weight doesn't make you exceed your payload capacity you should have nothing to worry about.