I agree with putting the correct amount of oil in when changing, start engine to let it fill up the filter etc., stop engine and give it a little time to drain back down then check and this is the level when full.
Now from my experience with my 84 500SEL, If i change and check as above, it will show FULL on the stick. If i take the car out and run it on the interstate for 10 or 15 miles, put the car back in the exact spot the oil was changed. Stop it, let it sit for the same amount of time as when i changed and checked at the change, it will show about 1/2 qt overfull. The engine in this car holds about the same amount of oil as the transmission, and the oil expands about the same, thus the overfull indication when hot.

Does this mean I should add 8.5 qts when I change the oil or add 8 qts so it won't be overfull when HOT? I have read many times on the NG that you should never OVERFILL the oil.

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84 500 SEL (307,xxx miles)