Towing in 3rd gear would only help you at highway speeds but does nothing for the lower gears / lower speeds. My truck with 3.55 ratio is great at everything from 10-15 mph on up and even does well on the mountain roads in Oregon pulling my 7k lb. trailer. The 8-speed helps this a bunch too. Where it could use a little more is from a dead stop up to 10 mph. This is why I was / am considering a rear end gear set change.
