Well according to amd the 555 max temps are 70C.
So i'm guessing those temps are good if the load
temp is only hitting up to 60C.http://products.amd.com/en-us/Deskto...il.aspx?
Maybe your case poor airflow , hot air can cause that
Why you don't test in midle oc, I think for to know you must test it step by step, from 3.6 test, 3.8 test .
Try use Intel burn test for quick time. Maybe 15 minutes