I want to clock my iPhone 3G CPU from 412 mhz to 620 mhz but is it safe to do so?

I know that the iPhone 3g cpu's standard clockspeed is 620 mhz but Apple underclocked it to 412 mhz.

I want to clock my iPhone 3g cpu to the standard 620 mhz that it was designed for and nothing higher than that. But is that dangerous? I don't want my phone to start over heating, fry, or catch on fire, or anything like that. BTW, I don't want to buy a new iPhone just for faster cpu. I like my iPhone 3g just the way it is.

PS: If it's safe to clock my iPhone cpu up to the standard 620 mhz, how do I do it? I heard that it's been done by some people.

I don't think it would be, just because they probably clocked it down for a reason. So there may be a lot of problems if you do.

Can you OC it, probably; is it safe, no. Running OC, degrades your computer components faster, so they fail sooner.