No, you should be fine, if your water cooling you won't have any issues, That Chip held the world record for OC'ing CPU class last time i checked. 5.0 is not problem for that chip
Unfortunately without dropping cores 4.9 / 5.0 is about as high as you can get on big air / water. You have to pump a *lot* of voltage to get it that high. I was at 1.56V (1.45 is the "max") to hit 5GHz.
Anything above 4.6 isn't really worth it.