how much is too much (engine oil overfill)

[4793]

'02 K2500 with the 8.1, 6 1/2 quarts with filter (standard) change. Using a 2 quart measure, the ordinary procedure is "3 full measures, wing the 1/2 quart, and make sure the oil level is toward the upper mark on the dipstick".

This time around, I got into a zone or something, and just as the last of the fourth full measure went down the fill tube I realized "dummy, this thing is gonna be too full". Consulted Dr Search Engine and got inconclusive results- though it seems less risky in a big slow running engine like the 8.1 I decided the safe thing was to drain off that extra quart and a half. Messy, and not fun.

I believe I learned my lesson, and am just curious to see if there's an informed consensus here as to the question asked in the title.