The ram speed is a ratio of the bclk. You should be able to change the speed of your ram in the bios without having to overclock.
A friend of mine said that the fastest thing is if you ram and cpu have a ration of 1:1 and that the standard frequency of ram were this occurs is 1066mhz. So I have to oc to achieve 1600mhz and a 1:1 ratio. Now I don' really know what it all means but thats what I was told.