I would try 150 fsb and a 1:1 (cpu/mem) ratio, if you're board is so equipped. Those settings should be pretty safe. If the system is unstable, bump the cpu voltage up by .025 volts from the default setting (which is usually about 1.47-1.5 volts). On some boards with an agp/pci lock setting, higher fsb is possible. If your power supply is generic as many are, your system may be less stable when overclocking. It won't hurt anything to try the 150 setting.