Tweaking

I recently built my own pc for the first time as a gaming pc and it is running very well around 300 fps on cs source, 150 on world in conflict and this is with everything maxed out but despite this i still feel the performance is lacking sometimes compared to the parts especially with games such as WoW where i get 60 fps at max graphics which i consider to be lower than expected considering the hardware.

This in mind, i was wandering if there are any settings or options i should be changing in order to tweak the performance of the PC or any tricks anyone with more experience knows.

Its running intel core i7 overclocked to 4 ghz.
6 gb tri channel low latency ddr3 1666mhz,
2x gainward gtx 260 1.8gb graphics
intel ex 58 ud5 mobo
vista 64 bit.

thanks in advance for any help.

Have you manually set the RAM speed/timings/voltage in the BIOS? Have you ensured the RAM is running at its rated speed using something like CPU-Z?