There appears to be two versions of the Chevy 454 engine which your Airstream may be equipped with: Throttle Body Fuel Injected and Carburated.
Both versions require the following emission components:
- PCV (Positive Crankcase Ventilation System)
- ACL (Air Cleaner Pre-Heat Tube)
- AIS (Pump Type Air Injection System)
- EGR (Exhaust Gas Recirculation Valve)
- EVAP (Evaporative System)
- SPK (Spark Control - Timing Advance/Retard System)
In addition to the smog parts above, the fuel injected version of the Chevy 454 engine requires:
- CAT (Catalytci Converter)
- O2 (Oxyegn Sensor)
Both engine emission classifications (California emissions legal and 49-State emissions legal) require the emission components as described above.