My 965 is running at 3.8 now on stock volts and not breaking 50 with either Prime or folding. Seems 4.0 should be do-able with my H50.
The breaking-in of my AS5 definitely dropped temps by a good 3-5 degrees on load.
@Tex: The temps are very believable. Its what I'm getting with my 965. I guess it was coz you said it in F, and not C...lol