You can run what ever heatsink you wish, bumping the clock won't kill your CPU. When the tempurature reaches the CPU threshold it will throttle and or shut down, no damage. Over volting is where the danger lies regardless of your cooling solution. I've been overclocking for many years and the worst I've done to a modern chip was to have it's OC potential reduced. IIRC it is a P4 2.4 I had running at 4.0 for about 5 years. Overvolted to the high end of the scale for that many years 24/7 just wore it out and one day I woke to find it had shut down. After reboot the best OC I could get was 3.6 so sadly I retired it.
After 5 years it was obsolete anyway but I still felt bad putting that system on the shelf.