No bad temps considering it is on stock cooler, but your 3570K goes all alone to 3.8 GHz, so 300 MHz is not a big deal really.
As a ***reference*** use TCASE 67.4C, which is the max temps for your CPU.
You can get a $30 CPU cooler, then push it a bit more.
Hyper 212 EVO http://www.newegg.com/Product/Product.aspx?Item=N82E16835103099