You have a decent aftermarket HSF, so I wouldn't worry too much about the heat. Just go into the BIOS and raise the FSB gradually,
stress-testing with every step, until you hit 3.2 GHz. (You'll probably need to raise the Vcore up a notch or two, though.) Also, if you haven't done so already, lap the CPU heatspreader. Doing so to my Q6600 really evened out the core temps.