Take out the crappy supplied bolt that comes with the pullies. After about 20,000 miles this is what mine looked like. So I went and bought a grade 8 bolt and will not be reusing this one since it is stretched to the point of looking like it has coarse and fine thread on the same bolt.
WOW I wish I knew what pullies I had, previsou owner put them on. I did not even know it had them until a ford tech looked at the car while I had it in the shop for some cc plates and he had stopped in to look at the dyno. He was not sure what kind they were but said he was pretty sure it had some pullies.