I know this may sound like a stupid question, but I am in California and have a limited selection of SMOG friendly headers.I have 1994 Trans am LT1 stock. From the pictures it looks like they are over glorified exhaust manifolds. Mine is 25 years old and rusted everywhere and needs to be replaced in the near future. So, is it worth it to get certified headers that adhere to CA SMOG requirements? Or simply just replace with stock exhaust manifold? Will there be a performance difference?