I agree w overshocked. I'm running 4.0ghz with H/T on air with 1.36V and 30c idle-65c full load. all within intel specs. with water cooling you'll be sitting pretty.
also intel states that their cpu's are tested to work for 50 years. Which obviously hasn't been proven but thats what they state so even if the life is shortened 60% you'll still replace other parts first. Its usually a function of the mobo or ram that kill a cpu