I am not sure if the motherboard will allow overclocking, Even if the CPU is a K version.
If the chipset isn't ether Z75 or Z77. He will still not be able to overclock.
He might be able to increase the bclk and get a little
more performance but Sandy bridge and up are designed to be overclock via the multiplier, which is locked on certain chipsets and non "K" CPU's. bclk overclocking can very quickly make the system unstable. So that is only recommended for enthusiasts to get that little
extra out of their already high overclock.
(he could actually also increase the bclk on his current setup if he could find a workaround or a supported BIOS. The K versions and supported chipsets are really "only" unlocking the multiplier)