OMC Exhaust flapper question

[ckelly]

I have a 1978 OMC I/O, model #990251U, 240 hp. I was in the process of replacing the swivel bearing and water pump assemblies, and when I removed the outdrive from the boat, I noticed a damaged exhaust flapper wedged in the exhaust cavity in the intermediate housing. I found (2) N.O.S. replacements, but can't find any information on where they fit in the exhaust and/or cooling system. They are OMC part #981927. If anyone has any knowledge on where they mount, I'd love to hear from you!

 

[Droid]

Since they (2ea) are located on the engine block/bellhousing picture and the exhaust drop pipes connect to the bellhousing I'd guess in there somewhere. Sounds like a BIG job to replace them.