I just removed and reattached my heatsink with less heatsink paste, and temps are down about 6C. I was up to around 56C at max load, and right now I'm around 50C at load. Plus this time, I can feel the heatsink get warm.
I'm pretty sure I just had too much paste on the cpu. I applied it this time using the "drop of paste in the center" method recommended for cpus with heat spreaders, and it seems to be working fine. Hopefully as the paste settles and spreads I'll get another couple of degrees drop in temps. This is with the cpu at 2070. After I verify it works ok and remains cool, I'll probably bump the cpu multipler to run it at 10x instead of 9x, which would get me 2300mhz instead of 2070.
If the cpu crashes at 56C, then try increasing the voltage .05 or .1 v. That can help. Otherwise, get a better heatsink and try again.