my bad I just assumed you were in California. I don't see why you would have any problems putting that on a CA emissions vehicle. The CARB approval allows people to use a particular product on their vehicle making it not fail the CA visual inspection.
Ford makes the past GT500 and the upcoming GT350 on the same Mustang production lines in Michigan. Carroll Shelby's company Shelby American has no influence engineering or design wise on the Shelby Mustang's from Ford.
Shelby American in Las Vegas sells parts (99+% made by other manufacturers...