"You can tow to ratings."
No you can't... Very few if any trucks out there can actually, safely, tow to their so called max towing capacity. The problem is they all run out of payload long before reaching that magical, mystical towing capacity number.
There a lot of nonsense numbers posted above, your actual tongue weight {aka hitch weight} should be at least 13 percent of the actual weight of the fully loaded trailer. Less than that and you are setting yourself up for some serious sway issues. Don't forget to add 100# {+/-} to that hitch weight for the weight of the weight distribution hitch itself.
A trailer that actually weighs 7,000# fully loaded for any given trip should have a tongue weight of 910# + 100 = 1010#. This number comes off of your max payload before you load anyone or anything into the truck. I have seen a number of nicely equipped Ram's with less than 1,000# of payload {4 X 4 and crew cabs are very heavy} yet they carry that mythical towing capacity of 9,000# or more. You cannot have it both ways.
As always... opinions and YMMV
:C