What carbureator for 4.3L Chevy V6 in a Non smog vehicle and street cam headers Holley says the 390 cfm Small as 2.8L engines use that.?

Holley's recommendation of a 390 CFM carburetor for a 2.8L engine is far too small for a 4.3L V6, especially one with a street cam and headers. A 390 CFM carb would severely restrict airflow, leading to poor performance and potentially damaging the engine.

For a 4.3L Chevy V6 with a street cam and headers, you'll need a significantly larger carburetor. A good starting point would be in the 600-650 CFM range. The exact ideal CFM will depend on your specific camshaft, headers, and other modifications.

Before purchasing, consider these factors:

* Camshaft specs: A more aggressive cam will require more airflow, meaning a larger carburetor.

* Header type and size: Larger headers will also need a larger carburetor to effectively utilize the increased exhaust flow.

* Compression ratio: Higher compression ratios generally require more fuel.

* Intended use: A street-driven vehicle will have different needs than a race car.

Instead of relying on a single manufacturer's generic recommendations, it's best to consult with a carburetor specialist or engine builder. They can help you choose the appropriate carburetor based on your specific engine setup and driving style. They may even recommend a different brand beyond Holley, as several quality carburetor manufacturers exist (e.g., Edelbrock, Quick Fuel Technology).