Are these core temperatures fine?
I have a Gigabyte H87M-D3H, and a CM EVO 212 on the CPU, all in the Fractal Design Arc Mini (three 120mm-s and a potentiometer set to lowest).
Safe temperatures way under the TJ Max of that specific CPU. More importantly however is the behaviour/temperature of the CPU cores when you are running a test/full load. At the moment they are very good temperatures to idle on.