With Intel you're better of running IBT (Intel Burn Test), than Prime95, it will seriously shorten the amount of time invested in arriving at a stable overclock, we're talking minutes vs hours.
Once a stable point is reached bump IBT from standard to a higher stressing level and continue testing, (minutes not hours), instability usually requires a further voltage bump increase, once IBT gives you a stable success, continue to test for stability by running some GPU critical testing like the Futuremarks or similar benchmarking and see if it continues to remain stable, if it does then test with gaming.
As far as an exact amount of time there is no set amount of time for a simple raised multiplier increased Vcore overclock, other than old wives tales, or assumptions, because someone else told them, that someone told them, Blah, Blah Blah!
Your 3770K is a 3rd generation Intel CPU it's on board the CPU memory controller was designed to run at either 1600mhz or 1333mhz speeds, anything past those speeds is overclocking the memory controller adding additional heat to the CPU.
Many cannot reach their higher overclock multiplier wishes simply because some are stupidly trying to run memory speeds higher than 1600mhz, shortening the life of the memory controller, increasing the possibility of instability, and adding unnecessary heat to the CPU.
Those are the facts and are clearly stated at Intels website regarding 3rd generation CPUs, it's not Intels fault that some have purchased 2400mhz or similar high speed memory modules and are proudly running them waving their little flags completely ignorant of what they're forcing the CPUs on board memory controller to do.
Clueless to the extra heat load they themselves are creating, and wondering why they cannot get any further with their multiplier overclocking, well for what it's worth, IMO, the best way to get the most from your CPU is a little investigation into how it was designed to operate.