Obviously performance varies due to the silicon lottery, motherboard stability etc, but here's a quote from the article i linked below:
"..I can lower the voltage slightly and settle with 4.6GHz just fine."
1) several guides you can find via Google.
Example (with 4.5GHz settings):
http://www.overclockersclub.com/guides/intel_pentium_g3258_oc_guide/3.htm
*Whatever appears stable, I suggest backing off by 200MHz and test for a few weeks. Then raise by 100MHz and if stable I suggest going no further. That's only about a 2% difference.
CPU instability doesn't always show up in diagnostics or as BSOD. It can often show up as corrupted data or similar issues that take a while to appear. Those are the WORST problems.
2) Make sure BIOS for motherboard is up to date (v2.70, and it has an "EZ overclock" profile with that new BIOS for your CPU though it may not be of any use to you.)
3) DDR3 setup can also cause crashing so keep that at default or XMP and don't overclock it. XMP is probably best.
Other tests:
www.memtest86.com (free version, full pass, use default settings)
Intel CPU diagnostic
https://downloadcenter.intel.com/download/19792/Intel-Processor-Diagnostic-Tool
Other: Intel's overclocking utility (not sure if it's useful to you) https://downloadcenter.intel.com/download/24075/Intel-Extreme-Tuning-Utility-Intel-XTU-
I've used it for my i7-3770K and it worked fine, but I prefer my BIOS.