You have to Pencil or ulock the L1 Bridges on the processor first , this will allow you to choose a lower or higher multiplyer, than you can also increase the FSB to the appropriate desired bus speed.
Defogger kit works for unlocking the bridges, you can also use a pencil though not as good.
Is your processor a 200mz or 266mz core.
I have the 200mz core, a 1 gig oc/ 1.430, I used the defogger kit to unluck it.
Just put a trace straight across the L1 bridges linking them together so they form a straight line, being carefull not to overlap the bridges .