Ah! Excellent! (That is, if those screenshots are of your CPU while idling or not at a load.)
See how the temperature for CoreTemp reads 0C? That means it is working like it should. That's not sarcasm, that's just how weird it can be reading temperatures for CPUs can be. There are at least two types of temperature sensors for reading CPU temperatures:
1) The on-die CPU Core temperature sensors
2) The motherboard CPU Socket sensors
The CPU socket sensor is great for reading idle temperatures, but, given its distance away from the actual CPU, often reads 5-15C higher temperatures than what the core actually may be. The on-die sensors have their readings modified by a type of equation that allows it to be more accurate when at full load, but the idle readings tend to be weird - often reading to be sub-ambient.
I do not have much clue where you CPU Socket readings are, but at least we know that CoreTemp shows your on-die CPU Core temperatures readings (assuming those screenshots were taken at idle). Now, all you should have to do is put it on load, for which Prime95 will work great, and you'll see how well your cooling solution will work. Remember, 74C is your maximum, but you always want some leeway, so anything above 65C is a bit scary. Around 50C is preferable.