Grubby John I also have 11.5 quarts of
oil in the car with lines,
oil cooler, and accusump. Each motor is a little different and drain back in the motor may not be the same. I am sure you have done this all on level ground. I have the Tee pan from canton and fill the
oil level to the bottom of the windage tray. I marked the stick for this level with cold oil. The rest was to run the motor and fill the oil cooler and lines. Re fill motor and let sit for 1 hour for drain back. I then added 3 quarts to accusump and ran motor. No air in sump. Let oil cool. Checked the level and pressurized system. I don't get crazy with draining all the lines and cooler on a change. My oil doesn't stay with the motor for more than 500 miles of racing.
Look at it this way, over fill the motor 1 quart. With it running you are sure to have the pickup covered and not get any air into the system. If you go racing, this is a whole different issue.
Your rear main seal may leak a little if you over fill, add cardboard under the car, AFTER the car has cooled off. See a couple of nice garage fires from hot cars and cardboard, not a pretty sight.
Rick .