Frostytech.com review the stock Intel core 2 duo heatsink that ships with almost every model of Core 2 Duo processor. What's the gist of their excellent review, in which the Intel heatsink we all use is compared against 30 other LGA775 coolers? Simple, you can do a LOT better than Intel's heatsink for TDP=85W processors. Top of that list so far this puppy. Anyway, the Stock Core 2 Duo heatsink review is a good read.
"The nice thing about buying a retail Intel Core 2 Duo processor from the computer store is that it comes with a heatsink guaranteed to work. It may not be the coolest running heatsink out there, but at least Intel have ensured it runs quietly, maintains the appropriate thermal range for the CPU, and installs without much fuss or any danger to the CPU or motherboard. The Intel RCBFH design is engineered to be cheap to produce, easy to install, and thermally efficient. This is the stock Core 2 Duo heatsink, and it is generally speaking a well designed mass-produced cooler."