Hello again Jay4 Hand - have a look at this page:
http://bp6.gamesquad.net/bp6fsb.phtml
Using BP6FSB you can monitor the CPU temps and change the clock speed through software - ideal for what you want to do.
Move the FSB up in the smallest increments until you notice instability, then move back down a notch. Test thoroughly by running SETI@Home or a modern game. Once you find a stable speed and the temps aren't too high, go into the BIOS settings and set your FSB there rather than by using BP6FSB.
FYI, this program also works well in WindowsXP - I use it all the time to see my temps.