Ouch!!!!
Well, now it truly is a one piece muffler Jeff!
I don't know what they're using to bond the three separate pieces together, but the high temperatures, together with the oil in the exhaust are tough on whatever they used to "glue" the pieces together.
The OS muffler does use a through bolt, BUT, since the two halves of the muffler cannot rotate, due to the sorta square cross section of the muffler. I've been using the OS muffler for two years now, and have never had to tighten the through bolt
Y'know, since you have the pumped version, you might not really see any change in needle settings with the new muffler, since you're not using muffler pressure.
Let us know how you like the new muffler!
Pete