I can't speak to the LHT or HHT settings as I don't own a PG1000. I would recommend a medium heat setting and splitting the tails, lengthwise. Brush with butter as you grill and turn them meat side up & down as you go. When the meat is opaque and rather firm to the tough, they're done. Take care not to overcook or the meat with become tough.
Sorry I missed your post the other day.