Asrock b75 adjusting the core clock

Hey guys. i have the asrock b75,and although it says it is not overclockable will i still be allowed to adjust the core clock by a couple mhz with out chagnging the voltage ?im pretty noob at those things. or is changing the clock speed same as overclocking

i have the intel i5 3570 k and the motherboard is talking about is asrock b75 pro3

im not planning to do major overclocking because i have the b75 chipset but if i can change the core clock that would be great.