If you have the 4 switch and 6 switch dip switch near the primary 33/66 IDE port. If they are there you should download ver. 1.3 of the manual for dip switch(multiplier and frequency) and jumper sittings (voltages). Also there is a jumperfree jumper to disable before you can start overclocking.
Try 1004D version of the bios before messing with any betas. The beta would not let me boot because it freezes initializing my Syquest 1 Gb Sparq drive. So go with what works and has been released.
Just remember when you are all set overclock by 50Mhz at a time until it becomes unstable or won't boot. Then up the voltage .5 volts at a time. Always watch the temps when you first boot to see that you are cool enough. Afterward you can up the frequency to gain a little more.
Good luck!