I wanted to start out and say hi to everyone. This is my first post on the boards but I have been reading it for years. I am an avid poster on www.thirdgen.org so some of you may reconize me.

Ok onto the question.

I have a full bolt-on thirdgen that I recently wrecked and started as my new project car. I also have a 1995 bone stock Z. I would like to take the exhaust off the 3rd gen and put it on the fourthgen while the thirdgen sits. The exhaust consists of a hooker cat back and a catco cat back, all 3". I know that my thirdgen headers and y-pipe will not work because of the routing differences. I realize that I will also have to fab up a reducer to the stock y-pipe on the z to mate it to the catco cat. My main concern is intermediate pipe routing and hanger locating. How differernt are the two. Will the two line up with the same hanger locations. I also hear that the section of pipe over the axle is differnt between the two. Am I the first person to attempt such a thing.

 

Anyone? Even if you have done the reverse (4th gen to 3rd gen) I could figure it out from there.

 

The cat back sections are the same. Only difference is how it attaches to the cat or cats.

I ran a Pacesetter Stainless steel catback from a 95 TRans Am on my 86 Trans Am.



Only thing I needed to have done was connect my custom y-pipe to cat to the catback ,


Oh, and it sounded pretty bad-*** too.
http://www.transamws6.com/video/ZepherWS6.mpg
This a 305 TPI with a cam, headers, the pacesetter catback, and 3" hi-flow cat.

 

Thank you zepher. Since there is a difference do you mean that they do not line up at the cat and y-pipe? I realize that they are different sizes but that is not the problem. The cat is welded to the cat back so I would like the cat to at least line up with the stock y-pipe of the Z. I don't want to have to re-bend anything if possible.

 

They line up at the cat since both systems are routed the same.
If your y-pipe looks like it runs the same path as mine, everything should line up pretty good..

 

I looked at your pics and although your y-pipe is custom I still think it will work. I will have to make some measurements on both cars side by side before I do any serious wrenching. The cat currently is welded to the cat back and there is a 2.5" reducer on the other end. I think the stock y-pipe size is 2.5" for the '95 so I may just be able to weld it right there. I did notice that the hanger locations are slightly different. On the Z there are hangers on the middle of the tail pipe section and on the 3rd gen they are at the end near the muffler. No biggy but may require me to relocate some stuff.