I have the stock catback exhaust off of my manual '90 GXL. A friend has a '91 automatic vert with a bad muffler. I haven't been able to find out much of the automatic verts have a different exhaust system past the cat. I've seen they have quite a few parts that aren't interchangeable and figured I should ask.

Would my stock catback bolt onto the vert?

 

Yes. In fact, stock cat backs off any model, NA/Coup, Vert, or TII are direct bolt on's. Cat forward, TII's and NA's are totally different.

 

+1, everything from the main cat back is the same coupe to vert. S4 stuff is different, but it actually will bolt on.

on the S5's i think the pipe from the manifold to the 1st cat is the difference between the vert and the coupe, the vert has a big reinforcement right where the coupe exhaust would go. however the front cat seems to be the same vert vs coupe.

 

Good point. Some exhaust cans are round (primarily S4), some oblong (primarily S5). Both work the same. The heat shielding on the S5's drop down a bit more for the taller cans as added insulation of heat from the gas tank. So you're good either way as the S5 shielding you have is essentially over engineering if using round cans.

 

Exactly what I needed to know. Thanks a lot guys!