Fuel Blowing Out Carb Vent Tubes Under Heavy Throttle: Expert Opinions Please

From the Holley manual:

A “wet” level float adjustment can be performed on either the side or center hung floats, if the fuel bowls have provision for the externally adjustable needle and seats. This adjustment is made as follows. Start the vehicle up and move it out of the garage and into an open area where plenty of fresh ventilation is available. Allow the idle to stabilize. Turn the engine off and remove the sight plug from the primary fuel bowl to inspect the fuel level. If it’s been determined that adjustment is required use a large screw driver to crack loose the lock screw. With a 5/8" open-end wrench turn the adjusting nut clockwise to lower the float level.

Conversely, turn the adjusting nut counter-clockwise to raise the float level. Tighten the lock screw. Restart the vehicle and let the engine idle stabilize. Shut the engine off. Remove the sight plug to reinspect the fuel level. The fuel level should stabilize at just below the level of the fuel bowl sight plug hole. This same adjustment procedure is performed on the secondary bowl.