Ok. I set:
400*8 with ram/fsb ratio 1:1, ram 5-5-5-15
CPU Core Voltage - 1,42
DDR Voltage - 2.2V
CPU VTT Voltage 1.4250
ICH 1,55
MCH 1,45
CPU GTLREF - 67%
I run OCCT Linpack test for 1h and it didn't show any errors so it's a good sign, right? (with VTT 1,35 and MCH 1,41 it failed after 30mins)
The temps compared with Prime95 were insane though - up to 79C on the hottest core. But usually 74-75. Later on I'll try running Prime95 for 2-3h and see how it works.
If it'll be ok, I think i'll try lowering the Core Voltage to relax on the temps.