How far will my mobo let me oc?

You won't get 5ghz unless you have advanced cooling, so the point might be moot. Most p67 boards will net you 4.4 to 4.6 to on good air cooling, maybe a bit higher on water.

Hi.

Those 5GHz are just lucky thing of only few CPU (batchs), but is almost impossible to know if you can get hose 5GHz on that mobo with that CPU, you only can know that at the overclocking moment.