I just went from 30" to 33" tires and I really lost some power during takeoff and accelleration. I'm going to regear the axles next month and am going with either 4.10 or 4.56 gears. Soooo, what do you guey think I need for a trail jeep? I mostly do old logging trails and firebreaks with the biggest obstical being mud and the occassional hill.
I regeared to 4.56 recently; 33's until I get the $$'s to step up; with a four speed it is intolerable on the street (a five speed would be perfect, don't know about slushboxes). You know your jeep, you know what rpm she likes to cruise at; find one of the calculators on the web and figure out what speed you will be running at various rpm's and go from there (Randy's has one I believe).
Mine is a trail rig only, but does see highway time to get to the trail. My 258 doesn't like to go over 3k rpm; with 4.56 and 33's that means a top speed of between 55 and 60 mph. If I was going to do it over again (assuming keeping the T-18 four speed) I would run 3.73 gears and use a Tera 4-1 kit to get my crawl ratio.