Teraflex
Depends on what you plan on doing with your jeep. If you wheel hard and drop off larger obsticals, the longest arm of long arms is going to help. Or if your wanting to run 40+ inch tires then 6.5 is the way to go for sure(without cutting into the frame). Can you do in a 4.5" what you can do in 6.5? most likely. It all comes down to what you want to do with your rig. IF i had a 6.5 lift, i'd stuff some 47's under there and drive over a Honda.
I'm shooting for 37's but one size wider than I got now. I plan on doing the driveshafts and gears. I heard some guys were having trouble with the rear axle being to far back. Is that an install issue or is something I can get to prevent that?


