I better get out my money glove if someone has money to throw around.  In all seriousness though, here is how clocking works.  The fab joint makes a fab disk with a ton of cpus on it.  They test each cpus max speed and the "speed bin" them.  What that means is that all Core Duos available are made on the same disks and are the same cpu.  Some of the chips run better than others though, so they are separated into groups of speeds.  Now that I got that out, there is no way to tell how high any given cpu will go.  A Core Duo 2.0ghz may OC to 3.0ghz, but another may only go to 2.2ghz.

Hope that makes sense.