This is a brand new build so I haven't OC'd yet. I went with the e6850 for the clock speed just in case I don't OC. I never have but I want to try my hand at it. The Scythe fits in very nicely but the fan will only go on one of the four sides of the heatsink once it is mounted. Fortunately it blows right towards the case exhaust fan so it works out good. I haven't really put the Scythe to the test yet, so the jury is still out. So far though it looks like it will do the job.
Let me know if you go with the Thermalright and if it fits or not.
Cheers.