For late 2008/2009 Roush changed the type of pulley on their Stage 3 cars and M90 Roushcharger blowers, VMP now offers a pulley that fits! The old pulley was a keyed type held on by a bolt, these blowers can be identified by their straight ribs on the top. Thew new blowers use a press fit pulley with no bolt and a plastic plugs in the front, these blowers have curved fins on top. The new style pulley requires a special tool to remove and install the pulley.