There are actually 2 versoins of the 600/133, the older 600B Katmai and the newer 600EB Coppermine. You MIGHT be able to get the 600B to 650, but the 600EB is good for about 950 or more. Too bad that you already have a 133 chip, as the rest of your system parobably can't take much more than that. If you had the 100, you could set it to 133 and get 800, providing it is an EB processor.
Cast not thine pearls before the swine