Bclock is hit and miss mate, sometimes it's CPU limited ( but rare), mostly it's chipset dependant, sometimes mobo design dependant ( eg MSI Xpower has issues to boot at high bclocks) ... if you have a lesser IOH chipset ( X58) then it could be you are limited to 220 or even lower... no setting (besides QPI Slow mode) will get you over that... Cold might do the trick...

I have done 233-235 (no slouch mode) on both my RE3s with a bloomfield Xeon CPU : so it's not the board design. Some have failed at 220 or lower, while their cpu did far better on other boards : Chipset limitation...