The problem is that certain parts of the CPU will run hotter than other parts so even if the average temperature is lower some parts maybe running much hotter.
The first thing is to make sure that you have a PSU which has the 8 pin connector for your motherboard so it is getting the maximum power.
I would make sure that you run the cooler at maximum speed during any overclocking to see what limits you can reach too. It maybe that if you want to overclock higher you will need to invest in a better cooler.
TBH even 3.2ghz puts you processor in the same range as the X4 955BE(but with one less core) and this should be plenty fast enough for the time being.