Lift/larger Tires With Highway Gears?

[leverlution]

Anyone done it? I have a 2010 Silverado EC LT 4x4 5.3 with 3.08s in the back (6spd hd trans). I keep going back and forth on a vette, ATTEMPTING to find a 6.2L I want, or lifting mine (I love the truck). While I have a personal/work truck, I unfortunately have a need for 4x4 which the work vehicle is not, so the Vette is out. The 2010 is acceptable as is, and I love the MPG it gets, but I am worried if I put a lift and tires on it that it will just be too detrimental. The truck is hardly ever driven, it is only really used to drive steep mountain highways, and steep mountain trails. Ideally I would like a 6" lift with 35in ATs in case I get hit with a nasty storm overnight in the mountains.

 

A little off topic, but my truck has the Z85 soft ride suspension not the Z71. Are there any lift kits with similar ride quality at all, or would I be back to the Wrangler Rubicon style ride quality if I lifted it?

 

Thanks in advance.