Maybe it is easier to change the front Y-pipe with one from Mid America or Corvette Central. They have them without the cats. The big cat can be replaced with a piece of pipe. I would suggest, if you buy the Y-pipe, to take the car to a muffler shop so they can measure the pipes and install the flanges at both ends. That way, if you have to remove them for any reason, you can do it yourself. Also, check the catalogs: I think they have whole systems without cats but they will make a dent in your pocket.