Here is a shot taken of my SB8R that shows the U-shaped passage in the swingarm and the exhaust pipe feeding up to the split header, which then leads to the twin exhaust cans:
So the tube from the rear cylinder goes down through the arm, hooks up to the front pipe under the bike and then comes back up [as a single pipe] through the arm to a Y and then the two cans???? A'm i getting this correct???
On mine the header from rear cylinder goes through the arm and comes back up as two pipes too the mufflers, so there are three pipes going through the arm.