I did it with that same setup except I used a freezer pro 7 cooler.
What did you get the g3258 to reach safely and stable? X.XGHz
Sorry for the late reply, school, excuse, blah blah. So I used auto-overclocking. It went to 3.9Ghz. The cooler keeps it at a couple of degrees celcius over room temperature at idle. and it never goes past 70.
It shouldnt be going anywhere near 70 with that cooler at that frequency. I suggest you overclock like a real man through your bios with no auto nonsense. Also your cooler may need to be re mounted.
I should have mentioned that it goes to 70 running prime 95. Other than that, I believe it stays close to room temp all the time. I use auto because I'm too lazy (also time) to get into the details of messing with all of that bios stuff. The most I do is video editing and sometimes play minecraft so it's plenty for me. Also, if the auto-overclocking is hard on the processor, I don't really care because of the $65 price tag. It'll last plenty long enough until I have money to upgrade.