Combine beef and ham, with milk and eggs, onion, bread crumbs, salt, allspice and pepper. Shape into meatballs about 2 inches in diameter. (If desired meatballs may be smaller). Carefully arrange meatballs in Crockpot. Cover and cook on Low 2-1/2 to 3-1/2 hours.
Turn control to High. Stir in flour that has been dissolved in 1/4 c water. Add ketchup and dill weed. Cook on High for 15 to 20 minutes or until slightly thickened. Turn heat off, stir in sour cream.