In a skillet, cook sausage over medium heat, until pork is no longer pink; drain. In a Dutch oven, cook pasta shells according to package directions; drain and rinse with cold water. Using a pastry brush, coat sides and bottom of a 3-quart baking dish with oil. Pour half of the marinara sauce into baking dish. In a large bowl, combine eggs, ricotta cheese, 2-½ cups of mozzarella, ½ cup Parmesan cheese, Romano cheese, basil, pepper and prepared sausage. Stuff shells with meat mixture; arrange in baking dish. Pour remaining marinara sauce over shells. Cover and bake at 350F for 30 minutes. Uncover; sprinkle with remaining mozzarella and Parmesan cheese. Bake 5 minutes longer or until cheese is melted. Sprinkle with parsley. Serve.