* Engine modifications: A stock 440 will have different needs than a heavily modified one with high-performance camshafts, heads, and intake manifold. A high-performance engine needs significantly more airflow.
* Intended use: A street-driven car will have different requirements than a dedicated drag racer. A street car needs good throttle response at low RPMs, while a drag car prioritizes maximum airflow at high RPMs.
* Engine RPM range: The intended operating RPM range dictates the needed CFM. Higher RPMs demand higher CFM.
* Type of carburetor: Different carburetor designs (Holley, Edelbrock, Quick Fuel Technology, etc.) have their own characteristics and may perform differently even at the same CFM rating.
General Guidelines:
* Stock or mildly modified 440: A 750 CFM carburetor is often a good starting point. It provides sufficient airflow for most street applications.
* Moderately modified 440: An 850 CFM carburetor might be more suitable.
* High-performance 440: You'll likely need a carburetor in the 950 CFM range or even larger, depending on the modifications.
Recommendation:
Instead of asking for the "best" CFM, focus on your specific engine build. Research the CFM requirements for your setup based on your engine modifications and intended use. Consult with engine builders or experienced carburetor tuners for personalized advice. They can help you select the right carburetor size and brand for optimal performance. Simply choosing a larger CFM carburetor doesn't guarantee better performance; it can lead to poor throttle response and drivability if it's too large.
