I have 2009 GT500 with 35K original miles, and it appears one of the Cats is disintegrating? My question is, I would like to use the opportunity to swap out the Cats for some highflow ones, but have read that the Cats off the 2013 are actually better then the aftermarket ones? My 09 is running a Whipple M-6066 Supercharger, with the stock exhaust manifolds, and SLP axle backs. I have the luxury of living in California, so I can't do a Cat delete. Any helpful tips would be appreciated.