4 or 5
I changed mine once and used 5 i think.
But then I did it again and installed a B&M deep pan, then it took 8 quarts, I am sure about the eight part.
The thing I am unsure of is if the new pan was 3 or 4 additional quarts over stock.
Just fill with four, crank it up, leave it in neutral, and keep checking and adding until you got to the add mark.
As long as you have a few quarts in it and don't drive it, no harm is done.
When you get it to the add mark, drive it to get it hot, then come home and check and add again if needed.
Keep checking for the next few days after you have driven it.
It took me a couple of days to get my 4L80-E completely full after changing the pan on it.