Yeah dude, make sure your RAM can take 225 as well.
And for me I just started toying to, but havnt messed will the multiplier yet, because i think I require more vcore than im willing to give to the chip with a safe concience right now.
But just for perspective, ABIT has auto-defined settings to overcock to (that they tested). And for my chip, when I lock agp/pci at 66mhz, and up to 220 mhz FSB, they recooment 1.7vcore
So thats a .26ghz increase, and the regular vcore is 1.5v. Hope it helps.