The easiest way to overclock on the Intel platform is to simply change the frequency divider in the BIOS. To achieve the best overclock we try to stay with the timings that the XMP profile recommends. If we run into any issues we will bump up the voltage to see if we can get our system to boot and become stable.
The XMP profile puts this kit at 4000 MHz. I was actually really surprised when I was able to get a stable boot with this kit at 4266 MHz with timings of 19-26-26-46 at 1.4V.