Combine first 7 ingredients; reserve 1/2 cup butter mixture.
Sprinkle chicken evenly with salt and pepper. Place in shallow dishes or heavy-duty zip-top plastic bags; pour remaining butter mixture evenly over chicken. Cover or seal, and chill, along with reserved butter mixture, 8 hours.
Remove chicken from marinade, discarding marinade.
Grill, covered with grill lid, over medium-high heat (350° to 400°) 40 to 45 minutes or until done, basting often with reserved butter mixture and turning once.