Fuel flooding in sounds to me like carb is flooding. Could be cracked float, mal-adjusted float, or too much fuel pressure. Has the fuel pump been replaced with a new one?
New fuel pump pressures range from about 5-7 psi. If that carb is a Holley 1904 1bbl with rebuild kit, it will flood if the fuel pump is new because the carb rebuild kit contains a fuel inlet fitting that allows 3 times more fuel in than the original inlet fitting.
A rebuilt Holley 1904 can only take about 1.2 to maybe 2 psi pressure. Any more pressure will defeat the float and cause flooding. Under this condition, the engine will run fine at higher throttle because the extra gas coming in is being consumed.
Fixes for this:
Revert back to the original fuel inlet fitting and needle (if they are salvageable with a good cleaning).
If not, a fuel pressure regulator will work for a while. Not very practical and too expensive to keep buying regulators (many are not serviceable).
Thirdly, but much more invasive, construct an orifice in the fuel line ahead of carb inlet and tee off with a bypass line back to the gas tank. If you wind up needing to do this, look back at older post where I give detailed description and photos of this.