You have a kick butt core 2 duo, why overclock? I'd probably try it in a few years but those things are to precious to burn out right now.
But anyway, apart from trying not to rain on your parade here try not doing such a huge over clock yet. Also keep in mind when you adjust one thing the others usually adjust, so keep the voltage flowing and beware that not every component can handle that much heat. Does your RAM have heat sinks by any chance?
Buy an afterstock cooler. If your serious about actually doing that it's an investment you have to make. Spend 50 bucks and get the top of the line Zalman cooler. You won't regret it. If your really hardcore and have some cash to spend water cool it. I had a friend who actually got their temperature down to 12C with water cooling.
Google overclocking, their are plenty of resources, tutorials and forums out there to teach you. Not saying we don't want to hear about your endeavor's here, but you might get a much bigger response out of those sites.
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