The Borla is a great addition to any V8. It has a nice deep sound and has increased the the MPG on the road slightly. In town not so much because the wife can't keep her foot off the gas.
Do you have the Emergency Brake set? If not, try putting the transmission in Neutral and set the parking brake. From there press the center diff lock and chage to 4 Hi.
I second the Bridgestone Dueler A/T Revo. It is rated as the best wet handling All Terrain on the market. They come with a 50,000 mile guarantee. I have a set of 265/70/R17's on both my 4Runner Sport and Tundra 4WD.