Overclocked CPU, now what?

[Dayzed&Confused]

Hi 8 Pack, Congrats on getting a job at OcUK, though with your credentials it's hardly surprising. Anyway, I've so far clocked my 960t to 4Ghz at 1.414v, but hit a wall with my current cooler, what I would like to know is whether or not it is worth overclocking the CPU-NB and RAM, motherboard is an MSI 970A-G46. If it is worthwhile, how would I go about doing so? Also, is there anything I could do to the current CPU OC (200Mhz*20) to improve it without needing to raise voltages particularly?
Thank you for any wisdom you can impart.
Edit: RAM is GeIL Black Dragon 2x 4GB PC3-12800 1600MHz CAS 11-11-11-28

 

[Dayzed&Confused]

I'm hitting a wall with the CPU because anything higher overheats under load, so it should probably be safe to raise it once I've decided on and bought a better cooler. From what you've said, is clocking the NB and RAM the same principal as with the CPU, If so, what are safe volts for me to use on the NB and RAM?