Overclock pci?

Hi, I'm not sure if this is where this belongs, but here it goes. I was wondering if there was any benefit to overclocking the pci bus. I have mine locked at 33/66, but I have the option of 40/70(I think ) and one higher. I'd be afraid to try the highest option, but how about the 40/70?
Does it boost performance?
Will I get data corruption?

Any thoughts would be greatly appreciated.
Motherboard is in sig.

You probably wont see any performance improvement, but you can get corrupted data on HDDs so I advise you leave it at default. It aint worth it.