Absoutely!!! You need either thermal paste or some stock heatsinks come with a thermal pad. That is OK if you don't plan on overclocking.
If it has a pad, remove the plastic covering the pad and it will be fine if you don't plan to overclock.
If no pad, apply thermal greese. Very small amount spread evenly with something like a credit card.
Check
www.articsilver.com for guidelines about applying paste and mounting heatsinks.
Chas