Running live side pipes here in the west, you guys don't know what your missing.
Side pipes are such a big part of the cobra look so it's important they look right.
I made my own from stainless steel as I couldn't buy any in Australia.
For the OEM look you will need to do:-
2" mandrel bends merged into form collector, 3 1/2" short section then 4" main muffler section then back to exit in 3 1/2". The mufflers / cats slide in from the end.
Expect to pay around $3,500 for hand crafted stainless live pipes in Australia.
Dummies would be around $3,000.
Sorry don't know how to post pictures on this forum but I have put some in my gallery.
Here is how they sound
http://www.youtube.com/watch?v=t_0-5lvAo-I