I picked up a factory hitch, with the 2" receiver, off a '99 Astro and installed it on my '93 Safari. I am not sure why such a massive hitch is only rated for 2,000 pounds, but that is another story. I am interested in picking up a small 4x8 or 5x8 trailer off Craigslist, when I see a great deal. I am in no hurry. On the other hand, I would like to be ready when I see one. So, my question is what size ball would be the most common for these small trailers, and how much drop would you get, if you haven't seen the trailer yet?