Heat 2 tbsp. oil and 3 cloves garlic in a 6-qt. saucepan over medium heat; cook until lightly browned, about 3 minutes.
Add dried parsley, basil, tomatoes, salt, and pepper; cook for 60 minutes.
Add sugar; cook until reduced and thick, about 20 minutes.
Mix remaining garlic, pork, chuck, veal, provolone, ricotta, parmesan, pecorino, breadcrumbs, eggs, salt, and pepper in a bowl; form into eight 2 ½″ meatballs, about 6 oz. each.
Heat remaining oil in a 12″ skillet over medium-high heat. Working in batches, add meatballs; cook, turning, until browned, about 10 minutes.
Transfer to sauce; cook until cooked through, about 30 minutes.
Serve meatballs and sauce over spaghetti; sprinkle with parsley.