375FSB is stable with a bump in voltage to 1.4V, but 400 is not stable. I think I may have to settle for 3.GHz on this chip since I don't want to push much further than 1.4V really.
With a VID of 1.350v, you'll be absolutely fine going over 1.4v

Your chip won't overheat, especially with a noctua cooler. Try 1.4250v and see if that gets you further.

