Mounting and using the Hensley
I applaud your use of the Hensley with your new rig. It's a great hitch, perhaps the best, all things considered and I have towed a lot with one.
It was not clear to me if you have used the hitch before with your TV or if you have mounted one to a new trailer before. If so, then good luck and all I'd suggest is to call the seller and ask them to take a picture and measure for you.
If not, I have run into some issues in the past that you may want to think about.
The bumper you have on your TV can change things. You need to be able to get to the OCL (Over Center Latches) on the hitch and depending on how far the bumper protrudes past the hitch receiver and how far above the receiver it sits can mean an easy hook-up or a frustrating one. (I have the factory step bumper on my TV and it covers the tops of the OCLs so I have to use a 1" open end wrench to close them.)
If you are going to install the hitch yourself, read the instructions several times and make sure you have all the tools and drill bits to do the job. Have some help, because you are in for some heavy lifting.
If the dealer is doing the install, I'd ask if they have done one before. It's much more involved than the typical WDH and requires some fairly accurate measurements. (I did the install myself in the dealer's yard but the tech let me use his two air lines, drill motors and ratchets and it made it go a LOT faster!)
You may or may not need extensions to the chains and the trailer umbilical. if you need either and don't have them, you are not going anywhere until you do. (I made my own because they are not a common thing at RV dealers...)
Get the "tongue twister" from Hensley. That and the 3/4" wobble bar adapter in your cordless drill will make hitching MUCH easier! (one secret is to back in parallel to the centerline of the trailer. The tongue twister will move things over a bit if you are not lined up perfectly...hitching is very different from a common WDH hitch.
IF you know all this already, like I said, good luck! The Hensley is a fantastic hitch and you'll not be disappointed.
(have you checked tongue weight with the addition of the Hensley? I needed air springs to reduce squatting with my TV...)
SF Bay Area
'99 Ford E350 V10
'16 Rockwood 8329SS