ok, a couple of limiting factors...
1) your motherboard isnt the standard overclockers choice, therefore im not sure how it lets you play with the settings.
If you go in the BIOS there are a couple of numbers of intrest, the Front Side Bus and the Multiplier. by multiplying these 2 together you get your clock speed so if you can change either or both of these in the BIOS you can overclock.
2) your RAM is rated at 333MHz this is the standard FSB of your processor therefore uping the FSB will push your RAM faster than it is meant to go. The amount you can up this is entirely dependant on your RAM type, for example I have 333MHz OCZ but it will run at 360MHz quite happily (please note all RAM is different).
If your processor is an early version there is every chance that the multiplier is unlocked this allows you to change it, the limiting factor then as I understand it is the temp of the cpu (which should not go above 60oC under full load).
So if you can change the FSB and multiplier change the multiplier up in increments of 0.5 then run Prime95 for a couple of hours and see what the temp goes to, or buy new RAM 400MHz stuff and change the FSB in increments of 5MHz testing it in the same way. The FSB change has the most dramatic effect on performance.
let us know how you get on
Pentium 4 2.8 with M0 stepping.
Only air cooling tho