Weiand's Pro-Street superchargers represent the leading edge in technology for obtaining substantial performance gains (25 to 40% over stock) while maintaining everyday drivability and long term reliability. Some factors that contribute to the exceptional reliability of the WEIAND blower include a thicker-wall case and rotors, plus a more stable mounting pad to eliminate flex. WEIAND relies on close machined and set-up tolerances to provide the required boost. GENERAL RULE OF THUMB: If the crankshaft has a one or two V-belt accessory pulley, use a short-nose blower. If the crankshaft has a three V-belt accessory pulley, use a long-nose blower.