The headers are designed to be air-restricted, allowing for optimal airflow and performance enhancement without additional modifications. Material: Constructed from durable stainless steel for corrosion resistance and longevity Design: High-flow primary tubes measuring 1.5 inches with a 2.5-inch collector for improved exhaust flow Compatibility: Fits GM full-size SUVs and trucks from 1996 to 2000 with small block Chevy 5.0 and 5.7L engines Includes: Gaskets and hardware for easy installation and a secure fit Performance: Enhances horsepower and torque by improving exhaust scavenging and airflow.