Thanks PnB. I just got around to making the adjustment to the Y slip-ons. I didn't read your response to this post until today, and my resloution was similar to yours but i did not remove the cans or move them back. I had to install my PCIII and modify the stock fender last night to complete my rash of mods this month. So I took care of it last night.
Yes the Yoshi's do have a very "tight" fit, and their design tolerances are admirable. Unfortunately the tolerances in the stock y-pipe from the factory have alot to be desired. First off, the y-pipe seems to be shifted to the L slightly, and makes the L can sit closer to the fender and the R can sit farther away. Then the R side of the y-pipe seems a little lower than the L, so my solution was to use a couple of hose clamps to pull the y-pipe closer (up) toward the frame. I used some shower gasket found at the local hardware store and a thermostat gasket from the auto store to keep metal rubbing agains metal, and the heat. I had to pull the R side of the y-pipe up further to get the R can to move down. Now I have significant room between the underside of the rear fairing, and the Yoshi CF pipe.
Thanks for tunung in.