What FSB speed is your CPU running at? If it is 200MHz (aka 800MHz), then it is a C. If it is 133MHz (aka 533MHz), then you have a B or A.
Regardless, I think you want to know how to overclock, not the overclocking potential of your CPU.
Your motherboard essentially has all of its overclocking abilities stripped because it is an OEM board. You can try using clockgen (google it), but I wouldn't reccomend going too far as your PCI bus will get out of spec and there is the potential to lose data on your HD. Also, it's possible that clockgen may not work for your mobo. I'm not sure which version you would need. You may have to do trial and error to find the correct version.