Your ambient temperature is a bit high, accounting for your temps.
I like OCCT for stress testing.
It gives you a graph of temperatures, and will shut down at 85c.
Haswell actually runs cool until you need a high voltage.
I expect that you can oc to the 4.0+ level without a problem.
Do not worry about damage, the cpu will downclock or shut down at 100c or sio to prevent damage.