I assume you are using this dough recipe, by Alton Brown, at http://www.foodnetwork.com/food/recipes/recipe/0,,FOOD_9936_13823,00.html
. That is not a recipe I personally favor because of the high amounts of salt and sugar.
After weighing two cups of flour like you did and converting your recipe to baker’s percents, I get the following:
100%, A-P flour, 8.90 oz. (2 c.)
68%, Water, 6.08 oz. (3/4 c.)
9.6%, Sugar, 0.84 oz. (2 T.)
5.7%, Salt (Kosher), 0.51 oz. (1 T.)
1.65%, Oil, 0.17 oz. (1 t.)
1.19%, Instant dry yeast (IDY), 0.11 oz. (1 t.)
If my numbers are close, the salt is excessive (exceptionally so) in my view, as is the sugar. The instant dry yeast is also on the high side but it will be necessary to compensate for the high levels of salt and sugar. It sounds like you did not cold ferment the dough in the refrigerator, as the Brown recipe instructs. Even though I don’t particularly care for the Brown recipe, and would not recommend it, if you use it you should follow all of the instructions. Otherwise you won’t be able to tell whether it is the recipe that is at fault or your oven. I have not had any personal experience with using granite as a pizza baking surface so I can’t comment on its suitability. With the proper stone and an oven temperature of around 450 degrees F, I think you should be able to bake a decent pizza although it will take longer to bake the pizza. If the top isn’t finished baking at the same time as the bottom, you may want to move your stone up another level in the oven, or else move the pizza off of the stone when the bottom is almost done baking and move it to a higher level in the oven to expose the top of the pizza to more heat.
I noticed in your tagline at the bottom of your post that you like the Famiglia pizza that you had in NYC. That is a NY “street” pizza. If you are interested in trying out a NY style dough, let me know and I should be able to find a dough recipe for you to use.