Stock coolers were designed with stock temps in mind. If you overclock, you make a cpu work faster and harder, therefore raising it's working temps. 2 things are necessary to alleviate the additional heat. Good airflow through the case and a good aftermarket cpu cooler that has a much higher cooling potential than a stock cooler. Many recommend a CM Hyper212 because at 185w, its well beyond the 125w of your cpu at stock speeds and should with decent airflow handle a 8350 upto @4.3-4.4 with some voltage considerations.
I'd not recommended you continue OC without some more thought into cooling, you run the very real risk of cpu death due to excessive heat.