Quote: What about the rest of the exhaust system on a mild 400 like this? Would going to 2.5 duals be a worthwhile investment instead of 2.25 duals?
Depends. My car had a compression bent 2.25" exhaust system on it when I bought it and in places on the curves that thing necked down to 1.75" or less. To me that's not acceptable. But if your car has a mandrel bent 2.25" system on it, I would say just keep it. If your system needs replacing or you haven't bought yet, go with the 2.5".
