Grill 1 hour or until meat registers 150°F on meat thermometer, turning and brushing with remaining barbecue sauce mixture for the last 20 min. (Discard any remaining sauce used for brushing.) Remove meat from barbecue; cover loosely with foil. Let stand 10 min. or until meat is medium doneness (160°F). Discard plank. Cut meat into thin slices. Serve with reserved sauce mixture.