i have a 8V, 5 speed, stock t-case and 5.12's and HWY is almost impossable(sp).  i mostly stick to back roads and streets.  the brakes are a issue too.  but sence you have a 4 door it might be better.  with an auto it might not be HWY able with 5.12's.
I've looked at the gearing and a Sammy T-case (1.2:1 in Hi range) set up behing the factory kick range box would be the perfec reduction, bringing me back to stock gearing #'s on the HWY.  Yes a toyota T-case would be stronger, or a 4:1 might be a little cleaner install but I don't believe either will give you the hi range reduction offer by the Sammy T-case.  Just a thought to work on later... ÂÂ
Using GV auto tranny Specs: (I couldn't find the kick ones)
engine RPM | MPH | tire size | Trans gear
-----------------------------------------------------------------------------
2793.4 RPM |removethispart|@ 60mph with 27 in 4th (Auto, in OD)
2742.6 RPM |removethispart|@ 60 mph with 33 in OD with sammy T-case
3826.6 RPM |removethispart|@ 60mph with 27 in 3rd (Auto, Not in OD)
3130.9 RPM |removethispart|@ 60mph with 33 in 3rd (Auto, Not in OD)
My 34" LTB's measure a true 33" if you are running a Mud radial they may measure smaller.
of course now with the 34's the Speedo will only be reading 49 MPH |removethispart|@ 60mph in 3rd...
I'll try to get pics up when I can but lately between working on the Kick and work, I've been short on time.  I made the 4 hr road trip this morning to get my GV springs and extra doors ÂÂ

half door project, Luckly I didn;t have to drive.  By this 5pm this evening I had been up 36 hrs,  gotta love shift work.
The brackets for the lift are not complicated but are very time consuming.  Hope to maybe get some pics tomorrow, If I get up before dark.