RockKrawler lift kits usually result in more lift than the advertised amount, especially on a 2-door. This is to compensate for extra accessories added. i.e. Heavy front bumper and winch.
On my two-door, my RK 2.5" Max Travel lift gave me 4 1/4" in the front, AFTER I added a steel stubby front bumper and winch. I ended up replacing the front driveshaft after my first trail ride with the new lift installed. I replaced the rear driveshaft while I was doing the front driveshaft, just to save time in the future.
On a JKU, the rear driveshaft angle is not as severe as on a 2-door. But, I'd recommend you save money for the front driveshaft, as this will likely need to be replaced first.
2008 2-dr Rubicon, auto,
RK 2.5" Max Travel, Fox 2.0 shocks, 37" Nittos, 5.38's, RR skids, Warn VR8000-S.
RIPP Gen 2 Stg 2 Supercharger.
"Don't give up 5 minutes before the miracle occurs."