Aloha from Hawaii! I'm new here but a long time Jeep owner (CJ, KJ, Cherokee). I finally got around to lifting my 2012 KK liberty Jet. I went with JBA 2.5" 'silver' kit and kept the stock (Jet) 20" x 7.5" wheels. Just got it back from the offroad shop and the here are the initial results of lift:
Tires: K02 275/55/20 (31.8" dia. x 11" section width) No spacers needed with moderate trimming of front wheel wells for no rub clearance.
New ground clearance: Rear diff. 9.9" Front (under lowest point of factory skid plate) 12.5"
Re-geard to 4.11 -- Speedo is on the money with no calibration

Also have a lower RPM of 1550 @ 45mph (local city speed limit) stock was ~1950
Added K&N C.A.I.
Added Modded throttle body from 'Dan the fast man' (bored out ~2.6mm
Replaced ignition coils, cables and plugs (TT platinum with .041 gap per densko tech support, slightly cooler than stock .043 - Idles much smoother
Replaced exhaust with Flowmatser (P/N 817607 Force II SS) Perfect fit and great sounding (mild but throaty when pushed)
Replaced stock brakes with PowerStop 36 series Extreme HD front an rear kit - perfect fit and much smoother than stock
Next up is brighter Headlight / fog light bulbs. Any advise fro reliable super bright LED drop in? Want 6000+ Lumens, white, Hi/LO and fogs to match
Links to pics:
https://drive.google.com/file/d/0BwvCI4 ... sp=sharinghttps://drive.google.com/file/d/0BwvCI4 ... sp=sharing