The Air Injection Adapter Kit is designed to adapt our Street Header Kit to the early style (81-84) air injection tubes. These early style air injection tubes connect to the manifold itself instead of the mounting flange like the later models do. This Adapter kit will bolt to our header flange and adapt to your air injection tubes. When installing these adapters be sure to lubricate all the exhaust bolts prior to removal. This will help prevent bolt or thread damage from seized up bolts. Use the supplied gaskets and mount the adapters to the header flange. When installing you air injection tubes to the adapter we recommend using a high temp, sensor safe silicone (Ultra Copper works very well) on the air injection tube side of the flange. This will help to seal the gasket up properly.