Fill a 10-quart pasta pot with 7 quarts of salted water and bring to a boil over high heat.

Heat a long-handled 14-inch braising pan over medium heat. Add the olive oil and garlic, and sauté, stirring, until lightly golden brown. Add the clams in the shell and cook, stirring, for 1 minute. Add the wine, clam juice, tomatoes, and red pepper flakes and stir. Cover, reduce heat to a simmer, and cook for about 5 minutes, until the clams open and the liquid has reduced and thickened slightly. Discard any clams that have not opened.

While the clams are cooking, add the pasta to the boiling water, stir, and cook until the pasta is softened but still al dente. Drain, saving 1/4 cup of the pasta water.

Add the pasta to the sauce and toss together until all the pasta is evenly coated. If the sauce is too thick, thin by adding some of the reserved pasta water, a little at a time. Add butter, parsley and salt (which may not be needed, as the clams are salty), toss together over low heat and warm together for 1 minute. Serve immediately.