I have a 340 with the dual crank pulley & single water pump pulley. Rear crank pulley is a 6-1/2" diameter & the water pump is a 6-7/8" diameter. From what I'm understanding that combo gives you a slight under drive on the water pump. I'm needing to get a little more fan speed at idle. I'm looking at CVF's pulleys where they are a 1 to 1 ratio on the pulleys & say they are for high flow applications. Is there a stock combo that I could use to achieve this?
