You guys may find this site interesting. Sergio is a regular poster here and has done some ground breaking work with mod motors in Cobras. The first link is the "Supercobra" section but you may want to look around at the other parts as well. Lots of pics and videos.
http://www.cobra4me.com/phpBB/viewforum.php?f=9
I had to include this direct link just because the sound kind of gives me a stiffie!
http://media.putfile.com/SCexhaust
Enjoy, Steve