Can someone please simplify my search for a new Exhaust shutter? I have a 1977 Mercruiser 120. I assume my shutter is long gone since I pulled the upper exhaust hose off and there was just a metal bar held in place by riveted tabs in each side. What shutter do I need to replace this? The Iboats site is next to useless as far as providing this information as it is based on original part number. The merc Manual does not tell you the part number.
