What motherboard do you have? Also what computer case and fan setup do you have?? My i5 3570k would overclock to 4.3ghz and the temps would still be fine on the stock cooler. Your temps are fine, but they are kinda high for 3.4ghz (whats your vcore voltage set to in your bios?) You can take off the two side panels on your case then run Prime95 and see if its an airflow issue!