Exactly, it's already a better PSU. The problem isn't overload. It's overheat.

Nope. No problems at stock. Problem comes when the PSU is pushed.

I'll post my results tomorrow, I'll do an open-air test, with fresh air for the PSU. If it still overheats, I think I'll RMA it. One to one exchange... I'll see what the shop allows, thanks for the tips.

Seems like nobody here has the same experience as mine.
EDIT: Well, one to one exchange is not possible after more than a week(it's now 8 days, sucks).

Idk, I'll ask for an RMA anyway. I would've opted for Corsair VX550W if I could, but stock wasn't available.

Btw, didn't I mention it was pretty cold on an open-air setup, to answer herojack41's question? One of the components must have been not mounted properly, is my guess.

Well, on to my calculations. A rail has 240W(20A x 12v). The processor takes 95W, the graphic card takes 75W(pci-e 1.x specs). That's 170W. The board itself takes 30W. Bear in mind that all of this calculation is an overestimation. Now see, I have 40 watts extra. I doubt overclocking is going to make any effect.

Hey now, I have an idea, thanks. I might as well try those molex to 6-pins given. I still have time to test stuff out. Well, time to split the rails. I'll report again tomorrow(gimme a break, lol).
Anyone has my PSU and does overclocking to such a point? I need user experience here. It's more valuable than theories.