Will this be enough for gtx 770?

Answers here:

http://www.tomshardware.com/answers/id-2311121/power-supply-requirements-nvidia-gpus.html#14243229

And no, I would not OC with a 500 watter,

According to nVidia

http://www.geforce.com/hardware/desktop-gpus/geforce-gtx-770/specifications

770 Thermal and Power Specs:
98 C = Maximum GPU Tempurature (in C)
230 W = Graphics Card Power (W)
600 W = Minimum System Power Requirement (W)
2x 6-pins = Supplementary Power Connector

According to Guru3D "at the wall" testing

http://www.guru3d.com/articles_pages/geforce_gtx_770_review,5.html

Subjective obtained GPU power consumption (770) = ~ 195 Watts

Here is Guru3D's power supply recommendation:

GeForce GTX 770 - On your average system the card requires you to have a 550 Watt power supply unit.
GeForce GTX 770 2-way SLI - On your average system the cards require you to have a 750 Watt power supply unit as minimum.
GeForce GTX 770 3-way SLI - On your average system the cards require you to have a 1000 Watt power supply unit as minimum.

If you are going to overclock your GPU or processor, then we do recommend you purchase something with some more stamina.
 
No.... according to the folks who build it, 600 watts is the minimum PSU size ... according to Guru3D, they think ya can get away w/ a 550 watter, but not if you OC. You **can** use a inadequately sized PSU, that doesn't mean that your PC will go up in flames .... but if you want warranty support, if you don't meet "minimum system requirements", no one has to honor that warranty.

General rule of thumb for stable OC is add up all your component load sand multiply by 1.5.