We have a 2004 4Runner, which is 15 years older, that has the same 4.0 L V6. We installed the Hidden Hitch several years ago, which is now the Draw Tite hitch. We were able to use a wdh since it is a frame mount. Increased our towing and tongue weight from 6000/600 lbs to 7300/730 lbs. We hooked up our 25', 6000 lb tt and towed a couple hundred miles on flat desert land. Once we got home we started looking for a Tundra since the trailer was too much.
4Runners just do not have enough weight and wheel base length to haul anything much over 4000-5000 lbs. We pulled our previous 2000-3000 lb pop-up several thousand miles and it did a wonderful job, even in the mountains.
We now use our 2010 Tundra to pull our tt and it does a wonderful job!
2014 Eclipse Evolution T225
2010 Toyota Tundra Crewmax SR5 4 WD