I would use OCCT 3.1:
http://www.ocbase.com/perestroika_en/
It is a bit different than previous versions though. It has a new Linpack mode which is similar to IBT supposedly.
Run the CPU test for at least 8 to 12 hours and use it first with large data sets for this time period and then with small data sets.Run the tests at maximum priority. It has built in temperature monitoring and you can set a maximum temperature for it to stop tests at.
Also I would run Orthos for at least 8 to 12 hours too:
http://www.techpowerup.com/downloads/385/
You need to run two instances and set the core affinity for the first two cores for the first instance and the last two cores for the second instance.
I would also use CoreTemp to look at temperatures too:
http://www.alcpu.com/CoreTemp/