Your temp is fine at stock clocks, try not increasing the voltage nearly as much to get to 4.2GHz, power usages scales with the square of the voltage so that 0.05V increase amounts to 3.8% increase in voltage and about and 8% increase in power consumption then you have the added frequency which makes it even more. When you OC you want to keep the voltage as low as possible.
Also, 70C isn't super hot, but i would see if you cant get 4.2 at 1.32 V, that would keep your temps in the safe range. I would also just double check that your fans are all running and that your heatsink is nice and tight to the board, my 212+ can keep my 955 below 48C at full load with 25 C ambient.
the temp probably even goes higher than 70C, it got to 70C really fast and kept rising so i closed it. And i can change my voltage by +-0.025V. 1.35 - 1.325 - 1.3 etc.
Also, whenever i go over 3.8ghz at whatever voltage my RAM goes unstable with prime95 blend test and i get occational bsods.
Also, if i put 1.3v in bios, it shows 1.25 volts in hwmonitor, if i put 1.325volts in bios, it shows 1.275 in hwmonitor. BUT if i put 1.35 volts in bios, it shows 1.4volts in hwmonitor and cpu gets really really really hot. Whats the problem here ?