What size carburetor does your V8 need?
A bigger carb is not automatically a faster car. Start with the engine you have, the RPM you actually use and the intake it bolts to.
Start with airflow, not bragging rights
For a four-stroke engine, theoretical airflow in CFM is displacement in cubic inches × RPM ÷ 3456 at 100% volumetric efficiency. A 350 at 5,500 RPM calculates to about 557 CFM. Actual airflow depends on the engine combination; this number is a starting point, not an automatic shopping prescription.
Match the complete combination
Write down displacement, camshaft specifications, intake flange, transmission type and intended driving. A mild street engine and a high-RPM race engine need different decisions even if the displacement is identical. Vacuum secondaries can be useful for street combinations; follow the carburetor manufacturer’s selection guidance.
Check the parts around the carb
Confirm throttle travel, return springs, transmission kickdown or TV-cable geometry, choke power, fuel-pressure requirements, air-cleaner height and hood clearance. The wrong transmission linkage can be an expensive mistake. Never assume a universal bracket has the correct geometry.
Buy once, then tune systematically
Use the manufacturer’s baseline settings. Diagnose ignition, fuel delivery and vacuum leaks before changing jets. Keep a log of each change and its effect. Our calculator estimates airflow; a qualified tuner can help select and calibrate the final carburetor.
Reference: Manufacturer technical information ↗