You may be able to use this as the proper bushing:
http://www.cherrybomb.com/Catalog/ti...-_ict214s.aspx
Unfortunately SummitRacing had the wrong description in their catalog so I ended up receiving the 2.375-2.5" adapter. I sliced about 5/16" off, down the length of this piece leaving the rolled lip. The part I ended up with was only $6.99 as opposed to $17.99, so it was all good in the end.
I used the band clamps to squeeze the adapters down so the could fit in the tips. That rolled lip requires a bit of force to reduce the diameter of the adapter..
It fits pretty snug. I just drove the adapter in to the tip until it met up with the rolled end. I didn't slice the exhaust tips at all, though I may if they loosen up. If I do slice them, I'll drill a small hole and then cut to the hole so it is less likely to crack. I used a band clamp but in reality without the slits cut in the tips it probably doesn't add much to the holding power. Some old fashioned muffler clamps would do the trick, but might be more visible. So far so good.
Pros, it looks pretty good and cost almost half the Perrin tips.
Cons, the tips are heavy and they are cantilevered out there a bit, not much clamp area, but they were meant to be welded.
I feel like a bit of a poser, but hey, the stock tips should have looked better!
Edit - I did all this in less than an hour with access to a cut off wheel.