Basically. LGA1156 processors support a max RAM speed of 1333MHz at stock BCLK with a 2:10 BCLK:RAM ratio, while LGA1366 processors only support 1067MHz at stock BCLK with a 2:8 BCLK:RAM ratio. A BCLK increase will likely be necessary in order to get you RAM up to 2000MHz unless your RAM has a XMP profile that will enable higher speed at stock BCLK.
Overall I'm not convinced that RAM speeds above 1600MHz do much if anything to improve performance. So I'd just focus on getting your RAM up to about 1600MHz and then focus on getting tighter timings after that.
Edit: Default RAM speeds for Sandy Bridge is 1333MHz.