I know it doesn't help you if you have already purchased, but I bought an Andersen gooseneck adapter for my truck. I bought the steel adapter rather than aluminum due to price but it is quite a bit heavier and about the same strength. The adapter fits atop your gooseneck ball and has a real large height adjustment. My gooseneck ball screws into a big nut welded to the support plate that is welded to my frame. I drilled holes and installed eye bolts for safety chains. I love the hitch as it is real easy to back up and get on the hitch which is easily visible in my rear window. I then drop the ball to where my 5ver is level. The receiver they gives you fits over the 5ver puck and there is a cable with knob to lock it in place once you are down onto it. The Andersen installs real easy but is a tad heavy so I tend to leave it in place unless I need the full truck bed. doing it again, I would probably spring for the 35 lb alumimum. I get zero trailer wag and it is easy to turn with no interference between trailer & truck.
https://www.amazon.com/Andersen-3220...id=1513643311&
sr=8-1-spons&keywords=andersen+3220&psc=1&smid=ALL4KQ853O 570