There are many things that can cause that effect with a Holley. First off, when you hit the gas, the carb is going from the idle circuit to the main circuit and there is a lot of transitional things happening between the jets, power valve, and squirters. If it just started doing this, and every other time in the past when you mashed the gas, I would look at dirt in the main circuit. I would recommend taking off the float bowls and metering blocks, cleaning and blowing out all the passages then replacing the power valve and putting it back together. I have run, built, and raced many Holley carbs ad when they work they are great, but they can be a real pain when they get dirt or bad fuel in them.....