Re: Help me build my Jeep.
You don't have to have 4.10s with 31s. However the factory had that gear ratio with the 4/V6. And it just happens to be a very good ratio for 31s. I currently have that tire size/ratio and I find it perfect. As far as the drive line goes, many people say you have to have an SYE, but I think I can set one up with no problem so it won't vibrate.
Re: Help me build my Jeep.
I had 31's with a 4.5 lift 1" tcd and lockers stock axels running 3:55 with no problems. I went to 32's and could tell a big diffrence in a drop in preformace. and keep in mind where I live is flat tallest thing I go over is an overpass :D
Re: Help me build my Jeep.
Obviously with me sitting near 7.5" of lift, it is a bit more top heavy than stock... But it isn't too noticeable, even w/ "high speed" lane changes on the highway... Only time I really notice the height being an issue, is when it is windy out from the side, I have to fight to stay straight on the road a bit... I currently have a 1" TCD on my XJ with the close to 7.5" of lift, and have no vibe issues... but have ordered a SYE setup to install once I return back stateside in a few months.. As far as having the 33's and 3.55 gears, not the greatest setup, but I still have no issues shooting across a 4 lane main highway every day to and from work... it has no issues getting out of it's own way, or pulling any trailers that I would ever pull with it... but I am still wanting to go to either 4.10's or 4.56's as soon as I can afford the gears and install fees..