Overclocking my AMD FX-4175

Ok still pretty new to the whole OC'ing scene but I think I've got what I want out of my CPU but I'm looking for other opinions and have a question of my own. I've slowly moved up and up to 4.7GHz on my Fx-4170 chip, did this by just adjusting the multiplier and the voltage. I've got it to run stable in Prime95 for 1hour (I know I need to do a longer test on it to get a 100% stable answer, but I feel pretty good with it).

My question is the voltage in CPU-Z and HWmonitor read different under full load than what they are set. My BIOS cpu voltage is 1.45 which is a little high from what I've read, the only reason I've put it up that high is while running prime95 CPU-Z and HWmonitor show 1.4v - 1.392v. I've read some about vdroop or vdrop but not sure I get it.

Just kinda wanna make sure this is a safe OC to keep and wont drastically shorten the lifespan of my CPU.

AMD FX-4170 - CPU
Asrock 970 Extreme 3 - Motherboard

Let me know if you would like any more info.

Thanks in advance for your replies.