My 1991 F-150 with a 5.0 V-8 is listed as 6 quarts capacity with a full size oil filter. (Fram PH-8A). But if I put in 6 quarts is shows it to be considerably over filled. I replaced the dipstick, and it was the same deal. I drove it on the highway several years ago from Lake Havasu to Tombstone, Az. and when I got back, there was tiny droplets of oil on the back window of the camper shell.
There was no other visible signs of oil leaking anywhere. From that point on I filled it with 5-1/2 quarts, which brought it right up to the "FULL" mark on the dipstick, and never had an issue since. And that was over 25 years, and almost 170,000 miles ago. Go figure.