FSB overclocking question?

I plan to overclock my e6750 by raising the fsb 5 mhz and running orthos for a day. i just want to make sure what this means though... when people talk about fsb, they are usually talking of 3 digit numbers like 267 or 333. It looks to me that my fsb at stock is 1333 mhz. I don't know what is up with that...