Felipe the ultimate is a 3 or 4 speed transfercase, will give you good crawlratio and wheel speed when you want it. For dirt roads and mud a 2.73 or 2.5 low range is pretty much the ticket, but it's to high for crawling unless you have an automatic with a nice first gear ratio. Also the heaviest flywheel/ inertia ring you could possibly put on there would be a great help since it would help keep the engine revved up longer, definitely would help from bogging down and getting stuck in a mud pit