your probably talking about the all terrain package. they came in 08 and 09.
Z71 Appearance Package $995
Includes 18" x 8" aluminum wheels, P265/65R18 on-/off-road, blackwall tires, fog lamps, body-colored outside mirrors and door handles, unique "Z71 Plus" decals, sill plates and instrument cluster, chrome recovery hooks, Rancho front and rear shocks, unique front bumper lower fascia with smooth surface, body-colored grille with unique chrome insert. Requires either of Graystone Metallic, Black, Blue Granite Metallic, Summit White, Silver Birch Metallic, Deep Ruby Metallic exterior colors. Requires Off-Road Suspension Package.
You have to choose either one of follows options:Vortec 5.3L V8 SFI Engine with Active Fuel ManagementVortec 5.3L V8 SFI Engine with FlexFuel