I have a 6" drop hitch adapter on my 35' Residency, and my Master Tow dolly fits great. The only thing that's ever scraped is the bottom of the drop hitch (I could get one of those wheels to attach underneath, just haven't done it yet), nothing on the dolly has ever made contact with the ground. When I get home tonight I'll try to remember to measure my hitch's ball height and report back here.