I'm noticed from screenshots of people overclocking, ther bclk seems to be very close to what it is set in the bios. For example, user said it's set at 195Mhz, from the CPUZ screenshot, I see that it's measured at 194.99. However, on my E758, the same 195Mhz bclk is read as 194.49 ~ 194.51. Is there a way to get it closer to set value in the bios?
 
Here's an example: http://valid.canardpc.com/45vtxt (bclk was set to 196Mhz in this overclock)

bdary
That's normal for the bclk.  I've seen that on the X58 & X79.  You're always going to see some fluctuation there and what I've always seen is a range from .04 to .07 variation under what is set in bios.
 
As far as I know, there is no way to change that.

Yup.  The bclock will fluctuate here and there based on idle/load and power states.  People sometimes say that your bclock will be more stable the more stable your overclock is.  However, I wouldn't spend too much time trying to get the bclock to sit exactly on where you set it.