Max safe Voltage for Athlon II x4 640?

ohiou_grad_06

Distinguished
Hey everyone, doing a little overclocking with my Athlon listed in the sig. On an old AM2 board, so having to actually undervolt according to bios. Intel CPU shows CPU to be stable in 10 passes.

CPU Z has me at 3.36 ghz current voltage at 1.25-1.28. According to HW monitor, during stability tests, I was hitting 1.46 volts under load. Temps are staying at 30-35 under load on the cores. Am I safe on these voltages or go down a little more?