1Place pork in 4-quart Dutch oven. Add enough water to cover pork. Heat to boiling; reduce heat to low. Cover and simmer about 1 hour 30 minutes or until tender.
2Meanwhile, in 2-quart saucepan, heat ketchup, chili sauce, brown sugar, vinegar, lemon juice and liquid smoke to boiling; reduce heat. Simmer uncovered 10 minutes, stirring occasionally. Remove from heat; stir in lemonade concentrate. Set aside.
3Remove pork to rectangular baking dish, 13x9x2 inches, or resealable food-storage plastic bag. Pour marinade over pork; turn pork to coat. Cover dish or seal bag and refrigerate, turning pork occasionally, at least 4 hours but no longer than 24 hours.
4Heat coals or gas grill for direct heat. Remove pork from marinade; reserve marinade. Grill pork, meaty sides up, uncovered and 4 inches from medium heat about 30 minutes, turning and brushing frequently with marinade, until glazed and heated through. Discard any remaining marinade.