A lot of 5th wheel manufacturers will not warranty the frame if used with a gooseneck adapter. Make sure of that before you do it. I did use one on an older 5th wheel that I had, but when I purchased my new unit I installed a regular hitch. The only downside to the gooseneck adapter is the hooking up an unhooking takes a little longer than with a regular 5th wheel hitch.
Dennis & Debbie Z (Retired) F415847
Pipe Creek, TX
2008 HR Endeavor 40PDQ / 2014 Grand Cherokee Toad