Header Adapters - NSX (91-94) - For Installing 97-99 HeadersOur header adapters allow you to use factory or aftermarket 1997 1999 NSX tubular exhaust manifolds. While the factory 1997+ exhaust manifolds do not flow as well as aftermarket header designs such as aftermarket full tubular headers, the factory exhaust manifolds can often be found used at used prices. The adaptor kit includes pipes, gaskets, and hardware. May require O2 sensor extension wires. Our kit allows 1997 1999 style headers to be installed