This is such a strange question to ask. But I have the same question. So I searched the forum: So many different responses to the same question for the same car and engine type. So I took it to Chevy, had them change the oil, and they said that they put in 10 quarts. I got the $100 invoice for the change and it says 10 quarts on the invoice. So I guess I am going with 10 quarts. But they said to make sure I pull BOTH drain plugs (not just the one up front) and that I allow it about 20 minutes to drain. Then they said to put in the new oil slowly, allowing in 10 minutes to drain the fill tank before measuring it. They said to heat the engine up, turn the car off, come back in 5-7 minutes, and then measure the oil level with the dipstick. Then add only what is needed to fill it up to, but not over, the fill line.
They said to let the oil drain for at least 5 minutes after I take off the oil filter also.
Maybe this level of waiting is over-kill. I am not sure, but I am going to follow these recommendations to the letter in my Z51.
Oh, and I see the super-charger has to have its own oil change as well, but not nearly as often as the engine oil.
Does this sound right to the forum dudes and dudettes?
No, it does not sound right for your Z51.
The first thing is that 10 quarts is too much.
The second thing is that for your dry sump, less oil is better than too much oil. The whole point of the tank on the dry sump is to keep oil available to pick up even in hard cornering. So, even if you are low of oil with the dry sump, you will be able to pick up oil in the tank.
Why is it such a big deal to NEVER overfill the tank? An overfill condition can result in oil going from the tank to the air intake. That can cause a whole mess of issues from a soaked air box and filter, leaking out all over the place, could coat the MAF sensor if it goes that far, and, heaven forbid, if enough of the oil ever got down past your intake valves into your cylinder, well, fluid is essentially incompressible... Bye bye engine...
This brings me to point #3: leave your oil closer to the bottom of the hash marks than the top of the hash marks. It is safer that way.
As for how to check the oil, do what is indicated by GM: make sure the oil is hot (hotter than the indicated temperature - I make sure it is even hotter than the minimum required temperature), turn the car off, and wait five minutes to check it. If you wait too long, the reading will be too low, and you might overfill it (which is absolutely what you want to avoid).
There are a ton of threads here on the forum for this.
During the pre-delivery inspection on my car, I found that the oil was overfilled from the factory (slightly over the top of the hash marks). I made the PDI guy suction enough out that I was below the middle of the hash marks. He said, "I would rather have it too high than too low." I said, "No, it absolutely will not
be that way. Take more out, and don't stop until I say it is okay." He, of course, complied.