Reply to "Stumble!!"

In order for you to keep a consistent fuel level in the bowls, you need consistent fuel pressure.

The higher the pressure, the higher the fuel level will be.

I find that even though Holley says the fuel should trickle out of the sight hole at idle, that the level is too high for going up or down a steep incline and you will get spillage through the boosters under those conditions.

I run an electric Holley pump with a Holley mechanical fuel pump with a pressure regulator. That keeps the pressure the most consistent, yet it still does vary, especially at idle.

That seems to be exactly consistent with the nature of the the pressure regulators. All seem to have about a 2psi variation in normal operation.

On a Holley, I also keep the level just at the bottom of the sight hole so it just doesn't trickle out.

Everything on a Holley is a compromise. The fuel shifts so badly under racing conditions in the bowls, that under hard braking the engine will stall.

What happens there is the fuel will slosh away from the metering block AND CAN spill out of the vents.

They are not good carbs for those reasons.