1600 ram is just higher quality 1066 ram that can be overclocked safely to 1600 speeds. That process will end up increasing the voltage from the standard 1.5 volts to the maximum of 1.65 volts. Any voltage higher than 1.65 volts can permanently damage your i7-930 CPU.
Why bother? You will get improved application performance, or an increase in FPS of perhaps 1-3%. Is that worth it to you? Not to me.
Overclocking your i7-930 should be very simple if you do not get greedy. Just raise the BCLK value from 133 to something like 150 or 160 in small steps and your cpu will be running at the speeds of a 975. I consider this a safe value. Leave the ram values to auto. Increasing the BCLK will automatically overclock the ram a bit, but you will probably still stay at 1.5 volts. Use cpu-z to verify all this.