BBK Performance Pulleys consist of crankshaft, water pump and alternator pulleys. By reducing accessory drag, BBK Performance Pulleys increase horsepower. BBK Performance Pulleys can benefit almost any engine, and can add up to 15 horsepower to your engine while improving fuel economy. Utilizing the latest in computerized lathe and milling machine centers, BBK Performance Pulleys are able to deliver unmatched quality and value. Available for many EFI models such as the popular 4.6L/5.0L Ford, GM 5.0/5.7L and many truck applications, BBK Performance Pulleys are machined from high-quality aluminum or steel in a polished or powder-coated finish. Installation is easy - everything you need is included with every set of BBK Performance Pulleys. While the installation of a BBK Performance Pulleys can have substantial benefits, there is a caveat. Because an underdrive pulley causes the alternator to turn at a slower rate, it may not be able to produce the current needed to keep the battery charged when running at idle. If your vehicle is idling a great deal of the time, you may wish to install only the crankshaft and water pump pulleys. That said, BBK Performance Pulleys can add up to 15 horsepower to your engine's output. All our customers want tremendous technical support while purchasing high-quality car parts. So of course we've established an always-online customer assistance hotline to address your queries. Everyone hates paying for shipping, so your parts come with completely free shipping on every order $50 and up. If you find a better price, let us know - we always beat any legitimate auto part price.