I have been towing with my wife's Suburban, using a ball mount in drop position. I have towed a standard 16' flat bed utility trailer, a 5'x10' Uhaul, and a 6'x12' Uhaul. The Suburban mount has been at the correct height for all of them. I just went to the garage and measured the Toyota mount on my 4Runner. In the "rise" position, as specified, the ball will be 3" higher than on the Suburban. Unless my springs sag too much (no air suspension), I'm afraid it will be too high. I will ask dealer about this in two days when I go in for warranty service, but I don't expect to learn anything useful.
Also, I am looking for an electric brake controller for my 4Runner. I have a Drawtite Activator II on the Suburban. There is much less mounting room in the 4Runner. Can anyone suggest a good mounting position that will be sturdy, unobtrusive, usable, and easily removable without leaving much damage? (I'm not asking for much, am I?) Are there any digital controllers smaller than the Drawtite?