I confirm anything below 72.6°C is fine (not considered overheating):
As for overclocking, since the operation of any Intel-manufactured product outside the published specifications for each part can result in data corruption and unreliable system behavior; shorten the life of your product, void the warranty of your processor, your desktop board and possibly other devices installed in the computer, while you are certainly free to use/configure your system as you wish, there is no technical support available from Intel, or through our product support processes, to do so. For further details regarding overclocking, please, refer to the following website:
Only P67/ Z68 is good for oc. maximum non-turbo multiplier could be set to 33х and the CPU Voltage to 1.100V.