This was achieved by simply dropping the multiplier on the processor and setting the FSB to 1600Mhz versus stock 1333MHz. Nothing at all was adjusted to the memory, the CPU just has better access to the available memory bandwidth and the numbers shoot up.
For a 4GB kit these sticks come with already scorching speeds. I was able to push up to 1164MHz and suspect I was badly platform limited. With a stronger MCH I imagine 1200MHz CAS5 is possible.