So I know this is an old thread but figured I’d chime in with my first oil change experience on my 2019 LT 5.3L (NBS). I have been changing my oil in all my trucks and vehicles since I was old enough to drive and have found that the amount going in is not the same every time. The dealer did my first change free at 7,000 miles. I just hit 13,000 and decided to do it again a bit early. (Still 6,000 miles between the last change.) I drove about 10 miles, let sit for 30 minutes and then drained. It took 7.5 quarts. I put in the extra half quart for the heck of it per GM’s spec and my dipstick read above the full mark. I ended up pumping the half quart back out this morning after letting it sit overnight. On level ground it reads just below the full mark on the hashed section of the stick. As others have said, it’s easier to add oil then take it back out. If it calls for 8 quarts, add 7, drive it a few miles then let it sit to a cold start. Few hours or over night. Top off as needed. There is always a bit of residual oil that takes a while to fully reach the pan. Readings can be off if you don’t wait for it all to settle before draining. You wouldn’t think that a quart over is harmful but I have seen seals go bad pretty quick from overfilling the crankcase. Oil is a lot less expensive than an engine repair or replacement. IMHO.