Actually the stock stocks wont work on a 3" system. The shocks act as the travel limiter in the front suspension as there are no bumb stops on a 2wd GM. What size tire are you looking to clear? IF you look under the thread created by ar_audio we installed an setup the lift for his 06 Crew cab silverado. Stock tire size was the equivalent of a 28" tall tire. We ended up with a little 5" of lift in the front an a 3" block in the rear. IT all depends on what tire you plan on trying to run. The backspacing of the wheel plays a major roll on what tire you can clear with no trimming. If have any questions or would like me to setup a reasonably priced setup just let me know. info is in the sig.

On ar-audio's crew cab we had to do some clearencng beccause the use of a 18x10" wheel, an a 33x12.50 Toyo M/T.