Trim fat from pork. Cut pork into 1” cubes. Cut chicken into 1” pieces. Thread 3 pork pieces on 8 of the skewers, leaving ¼” between pieces. Thread 3 chicken pieces on each remaining 8 skewers, leaving ¼” between pieces. Place skewers on a tray. Sprinkle salt and pepper evenly over pork and chicken. Cover with plastic wrap and refrigerate 15 minutes to 2 hours. Meanwhile, prepare Chipotle Barbecue Sauce. Lightly grease the rack of an indoor electric grill or lightly coat with cooking spray.* Preheat grill. Place the pork kabobs on the grill rack. (Keep chicken kabobs covered and refrigerated). If using a covered grill, close lid. Grill until meat is slightly pink in center and juices run clear, brushing generously with the Chipotle Barbecue Sauce halfway through cooking. (For a covered grill, allow 5 to 7 minutes, giving kabobs a quarter turn once halfway through grilling. For an uncovered grill, allow 12 to 15 minutes, turning occasionally to cook evenly.) Remove from grill and keep warm. Place chicken kabobs on the grill rack. If using a covered grill, close lid. Grill until chicken is tender and no longer pink, brushing generously with the remaining sauce halfway through cooking. (For a covered grill, allow 3 to 5 minutes, giving kabobs a quarter turn once halfway through grilling. For an uncovered grill, allow 10 to 12 minutes, turning occasionally to cook evenly.) Makes 16 sticks.