I don't know that motherboard, but I assume it allows you to adjust your FSB speed. You should easily be able to go to 166 MHz (and probably more) on standard voltage with that chip for something over 3 GHz.
There's a P4 overclocking sticky post at the top of this forum you should read and it'll give you step by step instructions.
Like a fool i just changed it to 155 and my computer failed. i've reset CMOS and will move up gradually. I've set it too 137 for the time being. Will i have to change the voltage settings to the cpu at all ?? With regards CPU-Z my chip is 1.584v.
You can up the core a little bit, but don't overdo it... The Northwoods should be kept below 1.7 volts as I recall or you risk "sudden Northwood death syndrome"
I'm surprised it wouldn't take the 155 speed. You may be running into a problem with overclocking your memory. You should set your memory multiplier to 1:1 while you see how far your chip will go, then figure out your max memory speed and timings.
Same with the other busses... lock the PCI in at 33 MHz. and the AGP at 66 MHz. You want to eliminate as many constraints as you can so you can figure out how far your processor will overclock.