I agree to have it "suck" the warm air off the heatsink rather than blow it upon it... I have a simple setup that works very well for a few less degrees... I have a piece of duct from a bathroom fan (commonly known as a "fart fan"

that is about 15" long and is clamped to the fan (an Alpha also but only a 6K rpm model) with a 3/8" cable tie then run to another 60mm fan mounted on the side panel of my case (Enlight 7237) where I had drilled a hole 2.5" in dia. and have both fans pulling all the warm air off the heatsink and exhausting it out the side... (side mounted fan is plugged into a fan header on the board with about 16" of lead). I have both my front intake fan`s (2 80mm fans inline) and my rear 80mm fan all pulling air in to the case except for the power supply fan that is in the exhaust mode... This setup keeps positive pressure in the case but keeps a ample supply of cool air being fed to heatsink while the warm air is expelled out the side and PS... It was worth about 7-9 degrees F... (a drop that is...)
I have a digital camera I can take pic`s if someone could point me in the direction of a good upload site...?