Another Staintunes question

I installed my new Staintunes pipes last night. The bike sounds and looks great..
I couldn't get the header piece to slide all the way on the catalytic converter.
It's about 1/8" short of the stop. Is this normal? The mufflers seemed to line up right into place, but the header bolt to the passenger peg is a little off.

 

On Gen 5 bikes there was a "packing" on the outside of the header pipe that had to be removed before the Staintune pipe could be installed "all the way on". The packing looked like a metal ring (fairly wide) that was a few mm larger in diameter than the header pipe, but once you started chipping away at the ring it was made of some composite of soft metal and some insulating fiber, wrapped around the header pipe.

maybe Gen 6 have the same arrangement?