Thinking of changing from the 3.73 to 3.42. Anyone done it? How much will it change towing ability? Should be able to fine tune it with efi, right? found this set for $399 AAM 11.5 11-1/2 14 Bolt 3.42 Ring & Pinion OE Gear Set [AAM11.5-342-OE] - $399.00 : JTs Parts & Accessories...