The original literature stated the 725 hp SS would receive JBA's 3" manifold back system. That is: stock ford exhaust manifolds w/JBA's 3" X-pipe w/high flow cats and 3" axle-back exhaust w/JBA mufflers. JBA could not get this system 50 state emission legal. Then there was talk about utilizing the factory 2.5" X-pipe and factory cats but going 3" from the factory X-pipe back and that fell through. Hence, the decision to just add the Borla 2.5" catback exhaust to be 50 state legal since Shelby is a manufacturer and has to be 50 state complient. Hope that answers your question.
This is the Shelby info. that has me confused...........the third item "JBA manifolds".
R