Cook the pasta in salted boiling water in a deep pot for 5 to 7 minutes.
Heat 2 ounces of the extra-virgin olive in a 12-inch skillet over moderate-high heat until hot but not smoking. Add the garlic and saute until golden brown. Add the clams, clam juice, white wine, 1 teaspoon salt, 1 teaspoon black pepper and red pepper. Cover and steam until the clams open, about 3 minutes.
Drain the pasta and add to the clams. Stir and simmer while you sear the zucchini.
Heat a 6-inch skillet with 1 ounce of extra-virgin olive oil. Sear the zucchini for 1 to 2 minutes. Do this at the very end to make sure they keep their natural color. Toss the zucchini with the clams and pasta.
Plate in a large bowl, keeping some clams in the shell for presentation. Finish with the fresh parsley and the remaining extra-virgin olive oil.