If you want to hold off on removing the gas block, get in there with a small allen wrench and wiggle it around a little and see if that cleans the ports out.
i have a small right angle pick that may work. if there is no crud in the ports it will be a miracle. the amount of lead chunks in the gas tube was unbelievable. still makes me think if the ports are open enough to pass the chunks, i may not have to worry about it being undergassed.