That would be a bit long, even for me
GoogleBooks is now indexing doctoral dissertations held at its various contributing libraries. I was a bit bemused to discover that my own dissertation supposedly has 750 pages. Granted, I do tend to go on at great length, but "will write a Trollopean dissertation" was not one of my goals in graduate school. (More to the point, I suspect that if I had turned in a 750-page dissertation, my committee would have engaged in some seriously Biblical smiting.)