Just priced the Bilstein's, there not exactly givin them away...
There's Bilsteins and then there is everybody else.
Not entirely sure on your Tahoe, but your body style (you still have the OBS style) with the Z71 package on pickups came with AC Delco shocks manufactured by Bilstein.
The current Bilsteins that come the closest to the Z71 valving are the HD's for the front, and Comfort Ride in the rear.
Casey