You are right, I have had a hard time finding exact numbers for the Ram hitch. I know that it is a class V hitch. By definition a class V hitch has up to 1200 lbs weight carrying load and 1700 lbs weight distribution load.
A class IV hitch has up to 1000 lbs weight carrying load and 1400 lbs weight distribution.
By deduction you can therefore assume that the Ram class V hitch is rated somewhere between 1001 and 1200lbs weight carrying (no WDH) and 1401 to 1700 lbs with a WDH.
On my last trip I didn't use the WDH bars to see how it would feel. I felt a little more porpoising, but nothing bad at all. For short trips, I may forego the WDH bars. For longer trips I would still use them. My tongue weight is around 1105 lbs.
