Yes 407 is my unit number. Hitch height worked perfect, I have 8-3/4" bed clearance , tows level. I would be happy to compare notes, and pictures. I do have some questions about the WD prep and how to winterize it. Do you need to winterize every year if you never hook up a WD? It has antifreeze in the lines there now, will it not just stay there if the shutoff is never opened?