dude jesus christ why is your voltage so high?
that is at the extreme upper limit of air cooling...and no i definitely suggest not running it that high with a zalman. it's not that it is not a good cooler (it is...it keeps mine blow 50*), but its the fact that any air cooler will have trouble dealing with that much voltage.
your performance increase from what you get at 1.6V versus what you get at 1.5V (ie the max overclock) is usually NOT worth the increase in temperature.
dude its restarting likely cos its too hot.