Flasker,
Did you remove the heatspreader yet?

btw, I've got a pretty decent 6000+ in the other thread. Does 3557MHz aircooled for SPi1M with TT V1 cooler (+additional cool air). CPU idle temp is 24-26C according to Coretemp (cooler base/Heatspreader temp is around 21C idle) - under load (quick SPi1M run) it gets up to around 40C Coretemp / 28C cooler base/heatspreader. 1.5V.

I didnt see any gain going from 1.5V up to 1.6 or 1.65V - might require better cooling to see the voltage scaling though.