2" Spacer lift kit for '09 Rubicon

My brother owns a 09 Rubicon Unlimited and is looking to add 35" tires. He wants to keep the jeep as stock as possible. So a lift kit with different springs, shocks, track bars etc are out of the question. We are looking into a 2" spacer kit from Rubicon Express. We were just wondering if 2 inches of lift on a long wheel base JK would cause any additional problems with the castor, having to drop transfercase, or driveline vibes( as mentioned before, we don't want to do any more work such as install different driveshafts, relocating track bars etc... That's why we feel 2 inches of lift would be safe, right?) Sorry for the newb questions, I'm a cruiserhead and I'll admit, I don't know much about Jeeps. Also anyone out there have some first hand experiance with this kit or spacer kits? Here is the link:
http://www.rubiconexpress.com/Product.aspx?part=RE7131