Jasong
Spend a few dollars on a freezer 7 pro.
Stock heatsink is carp
All my quads have them and they run DC 24/7.

IMHO
Swapping a q6600 for a phenom would be a mistake.
The q6600 is faster and the Intel chipsets are much better.


BTW
Is your q6600 a G0 or B3 ?
It makes a big difference the B3 runs much hotter and doesn't overclock well at all.
Run GPUz if your not sure.