Was too scared to fire it up without it's housing heatsink (so I didn't test the voltage).
Cleaned and re-applied fresh paste.
Re-assembled and even drilled the 3" (80mm) hole on the flat side and added a 2nd 80mm fan.
Btw, using a 3" hole saw without a drill press sucks!
Running at 350 to let the thermal paste cure a bit.
Getting about 5% hardware errors in first 15 minutes.
Will let this run a while before I step it up to 381.