C5 Corvette Long SystemDescription Features With race inspired technology built into every system, you're looking at the very best the performance exhaust industry has to offer. Our C5 systems are available with 1 3 4", 1 7 8" or 2" primaries with catted or non catted X pipe mid section. 1 3 4" mid sections have a 2 1 2" reduction at the flange to connect to stock system. Of course, these are manufactured using the highest quality 304 S S available and require no