Stock cooler.. And keeping in mind it's hyperthreaded meaning it's most likely hotter than the i5 counterpart (i5 750)...
3.2Ghz. If temps are good you could try 3.4Ghz. But overclocking with stock cooler is like driving a sports car.. with a 75 horsepower engine.
Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn!
"The sky was the color of a TV tuned to a dead station" - Neuromancer