Oh, before I lose this bit of info... WEIGHT:

Stock Manifold and First Cat w/ Heat Sheild and all = 9.9 lbs
Stock Cat Back (including 2nd cat) = 18.5 lbs

SuperCircuit Header = 5.5 lbs
1.75" Header Back (including cat, muffler and resonator) = 20.5 lbs

The header is 4.4 pounds lighter, but the exhaust is 2 pounds heavier. Complete system is 2.4 pounds lighter with weight shifted slightly to the rear.