I've been feeding the CPU with UnCore voltages up to 1.72V ( +560mV setting ), Vdimm up to 2.25V, and Vcore up to... hold your breath.... 1.62V on air ( you can laugh now ) and it's still clocking fine, like day 1

I'd say 1.65V UnCore is safe for 24/7 and Vdimm up to 2.1V for 24/7 ( you need to have the UnCore at 1.6V or a bit higher to keep the Vdimm at 2.1V for 24/7 without risking your CPU's IMC ).