The air system for the GTX560- 580 are awfull, to increase the air flow I would either get a PCI-E fan or get a case with high air flow and fans on the side of the case where the graphics card will go. If your card is blocking the air flow of the cpu, you risk of overheating and damaging your components.
The airflow of the gpu is being blocked by the cpu incasing. The cpu air flow is fine. I have this card http://www.newegg.com/Product/Product.aspx?Item=N82E16814125354
so gpu fans will not help.