I'll definitely consider the high flow cat, they aren't too much more expensive. To spend time and money on it I guess it makes sense to just leave it on after. I don't support pollution I just really enjoy my first v8.

 

Tom I just replaced mine from the Y back with a Walker Y CAT and Muffler kit all fit right and it is larger bore and has a nice sound to it. All told it was about $350 plus delivery. The Shop guy told me $450+ for just an after market CAT of dubious quality so I did it myself. Turned out I needed to get a couple extra muffler pipe U clamps. Its worth considering and it does the legal pollution control job required. (watch the CAT break in vid on Rock Auto that is where I bought it) It won't noticeably affect the power of a V8 and my 3.9 is running better for it.