well they my exhaust guy said it woud give it a deeper not so crazy tone, and i already bought mine but the dude who sold em to me only sent me one so i have to wait for the other one
if you look for Mopower open mouth grille or Danko Reproductions makes them. Some people might be selling their's on this forum. So do a quick search and you might be able to find one cheap.
You would need to buy the Danko Reproduction 68 Style Deep Dish Grille. pull the front fascia off. remove the vertical cross bar that is behind the grille that you have now and mount the new Danko and viola! I Love It!