This turbo cross-over tube is used to connect the two manifolds (sold separately). Choose the cross-over tube based on the transmission (and bell-housing) for optimal fit and ground clearance. The cross-over tubes are made from 16-gauge, mandrel bent 304 stainless steel and include v-band flanges welded on for an easy bolt-on fit. A universal cross-over component kit is also available for custom applications that need something a little different (requires fabrication & welding). These parts work with most common LS swap parts (i.e. motor mounts, swap oil pan, and accessory drive systems) & provide the basic building blocks needed to complete a custom turbo system for your GM LS engine