The Silverados differently have an engine lag when you go to WOT. I know you can have the engine tuned and this should change things up. My uncle has an 07 trailblazer SS that had the lag that's common. He had it programmed and change it completely. No it's pedal to the floor. 07 with the 4.8 is a turd wagon when it comes to go full throttle in a heartbeat. The LS series engines to me seem to be the most reliable engines GM has ever made.