I'm reviving this thread 'cause I'm still looking for help. I got a muffler shop to shrink and pull some 2.5" pipe sections through some donuts that will clamp directly to the stock manny's. But would still like a good look at the stock set up - as you said, the Y pipe portion - so I can build my 2.5" system the same way.
Thanks for any help in finding/taking photo's!!