Chevrolet small block crankshaft pulley Moroso 64110 50% reduction. Double deep groove pulley fits 1969 and newer small blocks with long water pump. 4.04 inch diameter. Precision machined from high grade, lightweight aluminum castings. Extra deep belt grooves provide added belt retention during rapid changes in engine rpm. Small pulley diameter slows fan, water pump, and alternator speed to reduce horsepower robbing drag. High rpm water pump operation is improved, reducing impeller speed below cavitation threshold. Uses 17/32 inch belt. Chevrolet small block crankshaft pulley 50% reduction Moroso 64110 Moroso 64110 HOURS: 11:00 am to 6:00 pm Monday - Friday Eastern Standard Time We welcome CANADIAN customers! For ordering information, click on "Orders To Canada" at the top left side of this page. We will not ship to freight forwarding - expediting companies. PAYMENT METHODS: PayPal, Visa, Mastercard, Discover, American Express, money orders.