Using the TV fender measuring process as a means to adjust a WDH will get you in the ballpark, and it seems that you have your TV's front suspension about as close as one can get it to it's unhitched height, and I believe your "hitched" measurement falls right within Ford's requirements.
Check your Ford F-350's owners manual under towing, I believe you will find that Ford is allowing for a little more tolerance when using a WDH in respect to the return condition of the front suspension on newer Ford models.
As mentioned, a CAT scale weigh-in can confirm all your weights, and also confirm that your WDH is sized/adjusted optimally. CAT scale how-to:
I also tow with the Reese HP Dual Cam, and once it's dialed in they are a great WDH with the integrated sway control.
Couple tips on the Reese Dual Cam:
* Make sure that the cam arms swing freely prior to attaching the spring bars.
* Confirm that the chain hanger brackets are assembled and attached in the correct orientation.
* Once you have your adjustments made, take your TV/TT combination to a parking lot and put your TV into a tight turn, stop, and get out and confirm that none of the WDH components are binding.
Feel free to post a couple close up pics of your WDH if you want a couple of extra eyes on your set-up. Also, there are a number of Reese Dual Cam threads in JOF as well.
Hope this helps.