Thanks for all of you I contact GM and they give me the RPO codes for car the Shocks should be (ZQ1 SMOOTH RIDE CHASSIS PACKAGE) according my RPO codes. I wonder if they can find door jamb sticker because it also missing.

The sticker for the RPO codes should be inside the glove compartment. Sometimes they do get ripped out or damaged.

Also, for a small price you can purchase a VIN decoding that will list every RPO code with the description of what it is. I have found this invaluable. For instance, for my Blazer with teh ZW7 Premium Ride Suspension, it uses a unique combination of softer rear springs with mechanically self-leveling shocks. When I did my suspension lift, I decided to keep the shocks and springs but to compensate I got extenders for the shocks.

Wow it's really smooth at they say ? I don't know I go with ZW7 or ZW1 because both are smooth

I really can't say as I haven't compared. I kept the set-up because it is one of their towing packages. I will be replacing the rear shocks in the spring when it warms up and I have time with the OEM types.