New Pair of Replacement Water Shutters,1 pair Required Per Engine.
Replaces Part #: 807166A3, 18-2732-9, 143481 , 14348A1 , 14348A2
For 1982-1998 Mercruiser 5.0L 5.7L V8 & 4.3L V6
For 1982 to 1996 engines, there are some 1996 and 1997 models that apply. . Fits oval 4" Y-pipes with round pin holes. If you have two rectangular holes for the grommets you need the A1 water shutters. If your Y-pipe changes size a few inches bellow the shutter you have a one piece manifold V6 Y-pipe and need shutter A2.
If you have ever overheated these tend to get damaged. Sometimes you will find pieces of them in the exhaust when you remove the drive for servicing. They help keep water from entering the engine through the exhaust.