Six Guns
Been using pitts style mufflers for about 20 years (G-38 first) a vibrator to say the least, any way I have found that if you add a third attach point on the far side of the can, can to engine you will no longer have it coming loose. ( it can't be to the firewall) you may have to find a welder to add a small plate or spot to drill and tap the muffler can for the support leg
If you need a pic of what I am trying to say can do.
Cheers Bob T
PS captmicom I have to say THANKS for your support