Sorry, the NHTSA has not posted this TSB document yet.
You can still get the detailed info from Chevrolet for this TSB. Call your local Chevrolet dealer's service department & ask for a copy of TSB# 04082004.
SERVICE PART FUEL TANKS WILL NO LONGER HAVE THE RETAINER NUBS FOR THE REAR HEAT SHIELD EXTENSION. THE REAR HEAT SHIELD EXTENSION IS NO LONGER NEEDED AND SHOULD NOT BE REINSTALLED ON FUEL TANKS WITHOUT THE RETAINER NUB. *TT