BBK Performance Parts - 2005-2010 Mustang GT - Mid X Pipe With Converters - 2-3/4" BBK Performance mid X pipes are specifically designed to be used with BBK full length headers to complete installation to cat back exhaust system. 2005-2010 X-pipes are made from 2-3/4" Tubing and feature a merged X to maximize the potential of Ford's 4.6L 3-V engine. Each BBK mid X pipe offers performance, quality and value that guarantees years of top performance for your Ford Mustang.