If this was a V8, it most likely had a Quadrajet.
They are variable cfm, but when fully open can get 1200 cfm through them.
Many people have made them into highly competitive carberators with some fine tuning. These are very adjustable, and can really work well when set right.
The biggest performance limiter was the air cleaner.
Most people turned the lid over to get more air to the engine.
