Zerk2012 :
That's a fairly low quality power supply.
You have plenty of watts. If you don't have a decent aftermarket cooler then don't overclock if you have one then 4.2 is fairly low and should take just a little power boost.
How much higher i can go when overclocking my CPU so it would still be safe if i had a new better psu? What PSU you would recommend if i need to buy a new one? My watt usage:
CPU: I5 3570K s1155 with CoolerMaster Hyper 212 Evo
GPU: GTX 970 Herculez 4GB (X2 Version)
Motherboard: z75 Pro3 s1155
RAM: 2x Kingston HyperX 4GB 1600MHz DDR3
HDD: WD Caviar GP/1TB SATA 3 64mb
then i have a LG DVD+-R/RW/DL/RAM, one case fan and some leds with it.
PSU: Corsair CXV2 500W ATX12V2.3 80+