The Reese Low-Profile 5th Wheel Trailer Hitch # RP30054 is designed to be mounted directly onto your truck's frame. Or if not the frame some sort of strong steel support connected to the frame. So you would be best off installing it lower than your wooden deck and you should measure 9-1/2 inches up from your truck's frame to see if it will be low enough to work with your fifth wheel trailer.
You also have to take the clearance between the trailer and the deck into consideration. You'll... view full answer...