You should read the book, if you're interested. From the book (p.84):

"Time and time again there appears in print the logical but false assumption that Boeing took its losing military C-5 bid and revamped it as the commercial 747. In fact, the 747 would be an entirely original design that owes nothing to the C-5."

That said, in the same chapter he talks about how GE developed a high-bypass turbofan engine for the C-5 and it was only because they had such an engine that the 747 became possible.

But really my only point is that you should read the book if you're interested.