If this El Camino is equipped with a Federal Emissions certified 3.3 liter engine, the AIR injection system is not required. If this Chevy El Camino is a California emissions equipped vehicle with a 3.3 liter V6 engine, the AIR injection system is required, and you'll need to find the correct exhaust manifolds which have the air injection ports on them.
Attempting to smog check your El Camino with the incorrect exhaust headers will cause the smog technician to enter "tampered" under the visual inspection portion of the smog insepction.
