If you're talking the CAK-38, CAK-38 II, or the CBK-38, they should serve you fairly well assuming you have good through-case air circulation and you're not going to try overclocking it real high.
Oh yeah, forget those speed ratings you see with heatsinks, likewise "AMD Approved". Look at the .c/w, or better yet, Joes heatsink rankings on the front page.
Hoot