You can also get one of these step bumper receiver hitches -- Box receiver attaches to step bumper and then a drop ball mount can be used to drop the ball further. Note that the tongue weight for this hitch component is less than that of a conventional bolt-on receiver hitch. Also, this receiver is NOT suitable for WDH.
Sometimes on the shelf at Wally.
BTW, there are three dimensions and one rating to a hitch ball. The size of the ball diameter, the thickness of the shank and the length of the shank. The ball will also have a capacity stamped into it. Many 1 7/8" balls have only a 2,000 lb capacity; UHaul
has one in catalog with 5,000 lb capacity.