Heat grill. When ready to grill, place chicken on gas grill over medium heat or on charcoal grill 4 to 6 inches from medium coals. Cook 15 to 20 minutes or until chicken is no longer pink in center, turning and brushing frequently with 3 tablespoons salad dressing. Discard any remaining dressing. Remove chicken from grill; place on plate. Cover; cool at least 30 minutes.
Meanwhile, place eggs in small saucepan. Add enough water to cover eggs by 1 inch. Bring to a boil. Immediately remove from heat; cover and let stand 15 minutes. Drain; rinse with cold water. Place eggs in bowl of ice water; let stand 10 minutes.
To serve, cut chicken crosswise into 1/4-inch-thick slices. Peel eggs; cut into slices. Arrange lettuce on large serving platter. Arrange chicken, eggs, tomato, avocado, corn and bacon over greens. Sprinkle with onions and blue cheese. Serve with 2/3 cup salad dressing.