When I hook up the utility trailers I use the lower receiver. The trailers ride with the front too high in the top hole, so the lower hole it is.
Probably a good idea to back up to the trailer and see which receiver tube gets you closest to the trailer height, and go from there to adjust the WD hitch.
2014 Chevrolet 3500 CC 4X4 Duramax, Tork Lift Tiedowns, TorkLift Fastguns, Superhitch and supertruss
2009 Jayco 213 SOLD
2008 Bigfoot 25C9.4