Alot of it depends on the chip itself. Some are more stable than others. From what I have read, 4.5-4.7 with air and 4.8-5.2 with closed loop water. If you go push/pull on the H60 in intake you should be comfortable at 5, depending on your chip.
Hope you got a good one!
Side note- What MB do you have?
(Edit) Im blind! I see the MoBo!