I've gotten 3.6 GHz on my Q6700 with an OCZ Vendetta cooler (similar to Freezer 7 Pro). Although I couldn't get it stable in tests, it never reached over 60 C on 100% load. As long as you're under that 60 C, I think you're fine. Some people go over, but I don't know if that's a really good idea. :S Btw, I haven't lapped my cooler or CPU.