Well, "MAXIMUM" +12v Wattage for the GPU by Nvidia says 120W and your PSU's limit says 360W so yep, easily OC your GPU, use the gaming mode or boost clocks, it'll be fine. Unless you do a BIOS MOD OC or OC everything to extreme. Don't keep it heavily loaded for too long (like 4-6 hours). Let the PSU cool down every few hours with a complete shutdown or hibernation (or even sleep).
If the +12v Rail wattage is overloaded a lot, or almost reached and is overloaded for a long time, say 6 hours, then it can burn internal PSU components, which can easily damage your hardware. I've experienced it all in reality with my open-case build so you can count on it.
UPDATE: As your PSU's build quality is just good, not that great, seriously...