We tow our 2008 Nissan Frontier, 4x4, crew cab, long box, using the BrakeBuddy Classic. With all that we put in it, it weighs in at 4800#. That's probably close to the weight of your truck. The BrakeBuddy guidelines for weight & sensitivity work perfectly for us. The unit has the ability to easily work well on even heavier vehicles. We have been using the BrakeBuddy for several years.
At first I was unsure that the BrakeBuddy would work. Since we have a long drive on a hill, I tested it on the rolling truck and it was quickly brought it to a stop. I was convinced it would work after that.
Bob Flight, Rochester, NY- '02 Travel Supreme