RE: MVVS 26IFS on a Twin
I have flex joint between the muffler and the tail pipe. I use a teflon sleeve and clamps. The 3/4" tube is supported inside the large SS tube you see on the side of the nacelle by silicon spacers (fuel tubing siliconed to the tube). I get some airflow around the hot tail pipe.
See if this makes sense. The third photo is the 3/4" tube into which I have installed the restrictor I machined.