pre-binned

Hi all, First post so be gentle. :-) Apologies if this comes across as controversial as it's not intended to be I'm just trying to get a better understanding of the delidding offerings from Overclockers. I'm soon to be building a new overclocked gaming PC which will feature a delidded 8700k...

Got a pre-binned Processor5 ghz chip from overclockersuk, can get a stable 4.8ghz MAX at 1.4v, cant get a stable 5ghz, tried 1.3 - 1.45v, the higher the voltage the more 'stable' it gets, but still bluescreens and crashes when stress testing, using cinebench,passmark,prime95, intel extreme, etc...