most 2600K is stable at 1.50-1.52 for 5.0GHz.
temp is ur enemy as I'm afraid u will need a custom wc kit to tame that insanely high temp unless if u're in aircond room.
H5O push pull can take care until 4.8GHz only. 5.0GHz on H5O hmmm it's gonna make ur proc toasted. Short single threaded apps ie Pi is fine but not for real life.
until u found a golden chip then that's another story etc.. good luck!