I've had great results with "Gibson Marine Power Tip Muffler Transom Mount 310002"

Mildly built 505, 560hp and no noticeable difference in performance, sound is surprisingly quieter but keeps the deep rumble

These slip in only drop about 3-6 dB but will choke a small block out of 500 rpm on the big end. A big block will suffer more. I have personally run and tested these with a dB meter. The GGB type offer the same SPL level reduction and no rpm reduction. Both my personal experience.
https://external-content.duckduckgo....176&ipo=images

Don't think your going to find what your looking for without something hanging off the back. I installed turn downs, was quite at idle and full sound running

Just ditch the thru-hulls and go through the prop if you "want it to sound like a ski boat".

Which ones did you buy?

Spent the last hour looking for what I bought and came up with nothing.

Pretty sure I posted pics in my threads when doing repower but have not been able to find them. Did find my repower thread but no pics of the turn downs. Not even able to find same type looking for new on line

The ones I bought were about 9 inch long after the turn so it put the tips about 4 inches under the water at idle. They were not clamp on they where flange mounted same as tips with sealant and 3 screws each.

Found the pics but still don't remember where I bought them

https://cimg2.ibsrv.net/gimg/www.off...782a916154.jpg
https://cimg3.ibsrv.net/gimg/www.off...4b72c91cba.jpg

I have accidentally run across those before but can't find them anywhere now. All are clamp on which with my angle cut tips I don't think will work. They were also kind of expensive and I'm having an emotional battle spending that kind of money on something I really don't want. I like the sound of the open exhaust at all rpm levels but do not enjoy the reversion I am getting. Thanks for the help.

BTW, 12db is a huge reduction. That cuts the volume down by about 50-70%, but I highly doubt they reduce it that much.