* Engine modifications: A stock 455 will have different needs than one with a performance cam, ported heads, higher compression, headers, etc. More aggressive modifications generally require larger carburetors.
* Intended use: A street-driven car will have different requirements than a drag racer. A street car needs good throttle response at low RPMs, while a drag car prioritizes maximum airflow at high RPMs.
* Driving style: Aggressive drivers might prefer a slightly larger carburetor for better acceleration.
That said, common choices for Oldsmobile 455s range from a 750 CFM to a 850 CFM carburetor.
* 750 CFM: This is often a good starting point for mildly modified street engines. It offers a decent balance of low-end throttle response and high-RPM power.
* 850 CFM: This is suitable for more heavily modified engines or those intended for performance driving. It can provide more airflow at higher RPMs but may sacrifice some low-end drivability.
Anything larger than 850 CFM is usually unnecessary unless you have extreme modifications and are focused solely on maximum horsepower at very high RPMs. Using a carburetor that's too large can lead to poor throttle response and drivability at lower RPMs.
Recommendation: Start by researching carburetor choices specifically for your engine's modifications and intended use. Consider reading forums and talking to experienced Oldsmobile enthusiasts. A properly sized and tuned carburetor is crucial for optimal performance and drivability. Don't just guess – do your homework!
