How They Make It:BDS 71-Series superchargersNothing shouts "hot rod" louder than a big GMC-style 71-series Roots supercharger sticking through the hood. But like many other hot rod parts that trace their roots (pun intended) back to the original OEM design, modern hot rod aftermarket superchargers have evolved to the point where the entire blower is built exclusively from aftermarket components. Today's 71-series blowers have significantly more capacity, higher efficiency, and greater reliability than the original OEM versions. One of the leaders in the field is Blower Drive Service (BDS), which started in 1969 operating out of a one-car Southern California garage building blower front-drive systems and quickly diversified until it became the first company to offer a complete supercharger system including the drives, intake manifold, case, and carburetors. Now, 37 years later, BDS is one of the leading aftermarket supercharger companies and operates from a 10,000-square-foot facility. The company uses aircraft-quality materials and CAD/CAM machining to manufacture high-quality components, but one thing that hasn't changed is the personal service-owner and founder Craig Railsback still mans the tech phones and custom-programs blower EFI systems. As for the future, would you believe a 20-71 case is under development?!-Marlan Davis