A 1999 GMC Sierra header is a great way to free up horsepower and exhaust note. Our exhaust headers are designed to connect to you’re 1999 Sierra catalytic convertor or mid pipe with no cutting or welding. All of our listed headers come complete with a quality finish and hardware when necessary so installing them on your 1999 GMC Sierra is straight forward. If you need help finding the performance header you want for your 1999 Sierra our experts are standing by at 1-800-780-1409.