First off, to 0patience, the engine and car were stated in the title of the original question so do us all a favor and read more thoroughly before responding like that.
Secondly, bdogjr, don't let anyone feed you any more crap about this issue. This IS A PROBLEM that GM acknowledges. Going through the same issue with a Monte SS, 50k miles, 5.3 engine, purchased new, always been babied & serviced at the dealer, etc. Today the GM service manager said "it is normal to go through 1 qt. of oil every 1,000 miles after you reach 30,000 on the motor." That means 3 qt. of oil in 3,000 miles, this isn't normal for any car!
This is the biggest load of BS I have ever heard. And GM just sent an alert about an oil consumption issue in this model and engine.
Go to GM and make your concerns known, this is NOT normal!