Want to use your existing exhaust manifolds with the MagnaFlow exhaust systems? MagnaFlow Performance manifold pipes are the answer. These pipes are designed as a bolt-in replacement to ease installation and are built from durable, mandrel-bent stainless steel. MagnaFlow Performance manifold pipes are meant for use with MagnaFlow Performance exhaust systems only. Includes 3 in. adapters. For use with MagnaFlow Tru-X exhaust system.