In all honesty 52C isn't particularly high when under load, though granted you wouldn't want that figure if the machine was idle.

As long as you keep an eye on the temperature and you don't start hitting the 60's and above then I wouldn't worry about it - Your PC will probably belong in a museum by the time the detrimental effects of extra heat kill the CPU anyway.

Again, the key to overclocking is firstly to ensure that you have proper cooling and then to do it one small increment at a time. Yes, it is time consuming, but it is vital that you step it up a notch and test it thoroughly before making another adjustment. Failure to do so could have you pushing the CPU too far and ending up with a burnt out chip as soon as you do something CPU-intensive on your PC.

It sounds as though your setup is stable and staying relatively cool, so just keep an eye on those temperatures and otherwise enjoy the free extra few hundred megahertz.