It sounds to me like you may have the wrong dipstick. I have done a zillion oil changes on my truck (OK, at least 50 anyway) and it is always at the perfect level on the dipstick when I add 5 quarts. If you want I will measure the dipstick in my truck for you (2000 5.9) to confirm the length and the area of the correct fill line.
Edit: I took the initiative and went and measured it. It is (from bumping the blunt end of the handle that touches the tube) 32 1/2" - 33 7/8" in the "safe" area and 36" in total length.
Last edited by olyelr; 04-16-2009 at 08:30 AM.