The 02,03 airbox on the ZO6 are very decent. There is forever the airbox debate. When people are changing to aftermarket, they really aren't seeing any drastic improvements and some none at all. I think a ZO6(02 or later) airbox would do you well. I honestly dunno about the exhaust.....maybe so. It will at least be lighter than stock C5 and also has a pretty decent sound to it. One of the ZO6 engineers said that they didn't leave too much low hanging fruit on the ZO6. Another words, everything breathes very well and you are not going to gain much with boltons. Headers are probably the biggest bolton power gain.