Your 1979 Chevy Truck needs to be equipped with the following smog
1. A PCV valve/system (Positive Crank Ventilation). This is the pipe which
leads from the top of the valve cover to the intake manifold.
2. An ACL (Air Cleaner Assembly). This is the air filter housing and the
duct that leads from the top of the exhaust manifold to the air cleaner
3. An AIS system (Air Injection System). This system is also known as the
Air Pump or Smog Pump.
4. An EGR system (Exhaust Gas Recirculation System). The EGR valve
recirculates exhaust gases to the intake manifold.
5. AN EVAP system (Early Evaporation System). This system includes emissions
components designed to introduce fuel vapors from the gas tank to the intake
manifold as opposed to the atmosphere.
6. A Catalytic Converter. Designed to reduce emissions after exhaust has
left the combustion chambers.