I bought a March Pulley kit recently. I've got everything appart and and seeing how it's going to go together, when I realize it's not. The blue dots are the ones that were going to be changed. On the crank, the outer pulley is for the blower, which was supposed to mount on top of the new crank accesory pulley. The purple thing is a spacer that needs to go between the 2 pulleys on the crank. Although the spacer fit w/ the old crank accesory pulley, it didn't with the new one. I called Toma(5.0 tuner), and he recommended using Auto Specialties one piece crank accesory/blower system. It's has a smaller accesory dia, and a larger blower dia. This will free up some hp from the accesories, and give me a couple more lbs of boost. I'm ok with the boost increase, since I'm only seeing ~5 on the gauge anyway.