Mattax said

In most situations not much fuel is drawn from the bowls. That is at low throttle, such as idle, decelerating, and cruising on local roads.
More power is needed and therefore more fuel is needed at interstate speeds. Its still no where close to maximum.
Only in something like a 1/4 mile run, in the upper gears at WOT, is the engine consuming a lot of fuel which needs to be replaced.
If this car is being raced or run at the track, then depending on the hp, rpm, pump, fuel, etc, a larger inlet may be helpful.
The larger it is, the more easily it can be pushed open. Pressure in the supply line is maximum when the valves are shut (unless a regulator is used).
It could be 6 or 7 psi when the inlet valves are shut. Some of the new pumps are even higher - which pretty much guarentees overfilling the bowls.
Down the track, as long as it maintains 3 -4 psi, often all thats needed. Again, all depends on the details mentioned above.


1970 Carburetion Fundamentals and Facts Master Technician Service Conference Series Filmstrip (Session 273)

1970 Carburetion Fundamentals & Facts, p3 The Float

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