fishtheclassic.net is the shamrock forum. Lots of good ideas from guys who deal with inboards. The group is great.
I don't have a picture of my setup since I sold the boat a few years ago.
I bought some silicone connections that I clamped onto my exhaust after removing the flapper. They are pictured below, but you need to get them long enough so they are under water while under way.
I also looked at something like this but it seemed like I a lot of work to accomplish the same thing.
