I have ready-lift keys cranked up and 1.5" Suspension maxx spacers. Lifted the truck up 3" and enough clearance to run 295/70r17 (33x10.50r17) Since Burbans can be ass heavy, I would go with 2" Spacers.
I have yet to run into any suspension problems and was able to align my truck perfectly. I am very safety conscience and did lots of research before lifting the truck. I have not found any true fact negativities on keys and spacers and I even tow a boat with this setup.
Here's where I got everything:
Ready Lift-
http://www.readylift.com/c-39-chevy...-1500-2000-2006-classic-2wd-4wd-6-lug-25.aspx
Suspension Spacers (The Tahoe Ones will work for a Suburban)-
http://www.suspensionmaxx.com/chevy-tahoe-4x4-coil-spring-spacers-rear-2001-2006
This is how tall I sit with the lift and tires (I am however a Z71, but shouldn't be much of a difference)
Me vs Stock LS 4wd Tahoe
---------- Post added at 09:54 PM ---------- Previous post was at 09:45 PM ----------
Here's a pic of a Suburban with Keys and Spacers vs a stock Z71 Silverado