IMO if it wasn't made for overclocking then they wouldn't make it in z77 chipset.
Your manual on your motherboard says it wasn't made for overclocking or something to that effect. Check it out it's one of the first pages.
Anyways I normally only buy 8+2 or better power phases but with the Intel boards they can def push the 2500K and 3570K chips to 4.5GHz because I have used the cheapest AsRock boards on several builds usually with an OEM 2500K or a 3570K whichever was cheaper at microcenter at the time I build the computer for the person.
I would not chance an unsinked 4+1 phase on an AMD cpu that you are planning to OC though. That is just my 2 cents... I caught a 970 MSI board on fire and that was with aftermarket copper sinks on the board. It took the CPU with it when the VRM lit up like a flare.