We may both be right.
I looked around to find a answer. I noticed that your book is 1954 and mine is first run 1952 when the tractors first came out.
In 1952 at serial #18094 they changed the tube but left the stick and pan the same. It went from 10.47 inches long to 11.25 inches long. This in turn would raise the stick 0.78 inches.
So more oil would be needed to read full on the stick. I wonder if .78 inches works out to one quart.
Ford may have found out 5 qts was not cutting it and changed it to 6 qts.
The question I now have is why the 600 to 801 manual says 5 qts but I am not able to access that info right now.
Like Dean my 801 is suppose to hold 5 qts but I believe 5.5 is more about right.