Like hornet said likely uncore issue or could be mem issue, with 166bclk and 2:12, memory is 166x12=1992mhz and uncore must be at least 2x mem (or no boot) so 24x166=3984mhz. Trying 201 with 10x multi raises both the mem and uncore, mem is now 2010mhz and minimum uncore is 20x201=4020mhz.

I would try 24x uncore, 168bclk, and 12x mem and if that works then it is a problem with the 10x multi. Some have had issues with particular bioses and certain dividers. If that fails to boot, then like Hornet said you need to raise qpi and ram volts, the extra 20 mhz mem and 40mhz uncore may not sound like much but you are getting up there where a little more uncore matters.