I used a March pulley kit on mine. I don't have a true serpentine but I use the wider belts. If you do have a serpentine, the blower belt will not ride on your other pulleys, it will be separate as mine is. The Weiand came with another part that is used for serpentines but I didn't have to use it. I would call Holley Tech and ask them. They seem to be very helpful.