I have a set of tri-y headers and a y pipe from the git kit for my 1982 trans am MSE which currently needs a cat converter. According to PA inspection laws I must have a converter on this car, which sucks. So, is it possible to mount a cat converter (w/o smog tubes) after the y on this car or do I need to keep a stock exhaust system. Thanks for your help and I included a picture of headers below.

 

You might be able to get a couple of these http://www.jegs.com/p/Magnaflow/Magn...63223/10002/-1 in the 2.5" variety (assuming your y-pipe inlets are 2.5") mounted somewhere. About the only way to know is to have them in-hand, mount the rest of the exhaust, and see if they can be fitted into the system.