Alright zed so i took it into today to look into a hitch cover ( turns out thats only made for the ltz bumper types i didnt know they were difrent tho lol) and had all my engine specs and everything looked over and your right its a 5.3L i didnt pay any extra it was just a mix up at the dealer when it was bought the sales man thought they all had the same 6.2 except the lt. How ever my z71 is on paper an LTZ package idk how that happened even the dealer was suprised to see my vin pulls up a Z71 LTZ soo idk sorry for any inconvinice. He did however say the 2011 Z71 Should be offered in a 6.2 due to complaints from drivers so there is hope for you. He also said the engine capartment is the same size on paper so it is posible to switch engines if your willing to buy basicaly a new tahoe lol. Hope u find what ur looking for