Originally Posted by
Firebirdjones
68,000 miles isn't a lot. However a lot of these LS engines have a history of some form of oil usage issues in stock form. Not all, but a lot. Piston slap, although considered normal if you asked GM, isn't something that is normal in my book. Even mild forms of it causes ring control issues, generally some oil usage is one result of that. Mild blow by for instance.
They also have a horrible PCV design that sucks oil in through the intake manifold. All the catch can does is stop it from entering the intake, but it doesn't solve the real issue of the PCV sucking oil.
Chances are you have one or both of these issues going on. I wouldn't see it as a cause for alarm but it certainly is a bit excessive in my opinion if I saw a quart missing after 3,000 miles. GM calls that normal too, lol. I don't see it that way. Personally I'd be looking for the cause and rectify it.