Yea the Phenom 2 is famous for under reporting temps. My old 1100t used to shut itself off when it read 65C which I can only assume is probably somewhere closer to 90C.
You won't get temps you expect. I set an upper limit of 64C for mine (practically I kept it below 60C under Max stress conditions and it worked without issue for a year at 4.2 @ 1.475. Mine has now been retired to work at stock in an htpc and is ticking over perfectly.
I used dug diamonds oc3d monitor to get the temps for reference: