But do not forget this is an experimental human drug licensed for veterinary use only.
This means there has not been any research conducted for human use. So anyone who gives you an answer on dosage of Febendazole is guesswork only, as really, nobody knows.
So I believe your searching for an answer which does not yet exist. The most you can do is try out different doses and stick with the one that works for you.
I'm using ScabDaggr's dosage guidelines simply because he's been using it for 3 years and has had success with no ill side effects.
But like I said, for a drug like fenbendazole, it's entirely experimental.