Ok, I know that Flowmaster makes or at least made a 3" inlet, dual 3" outlet crossflow American Thunder system. I want to order one for my GTA but Flowmaster's site dosen't give you pipe sizes when looking at the different systems. I was hoping that someone here has the setup and remembers what the part # for the entire catback was. Its a 1988 GTA with single 3" Cat.

 

you can look on summit racing's website and narrow the part number down by the pipe diameters. But for the American Thunder series with a 3 inch intermediate pipe is flo-17233. For a 2.5 inch intermediate pipe, the number is flo-17234. I would recommend flo-17233 because it is the same price, $340 and it has the larger intermediate pipe.

 

but it has dual 2.5 inch outlets, not 3 inch, because the 80 series muffler 43083 only has 2.5 inch outlets and a 3 inch inlet. I would recommend going to a muffler shop and having them bend pipe and install it and weld it for you, it will be cheaper and will be welded, instead of buying the kit.

 

I got the kit this morning. 17233. I got a better deal from the guy that i get my stuff from that what Summit sells it for not even including shipping. My cost with Florida sales tax was cheaper than their advertised price on the site. Im gonna have it put on around 2 today. I sure hope this thing makes some noise. The stainless tails are beautiful. I couldn't have gotten anything better made locally than what they are. Closest thing would have been the crappy chrome plated stuff or their overpriced stainless tips. The Flowmaster stuff is NICE.

 

Had it installed this afternoon. Man, that is the most awesome exhaust I have ever heard on a 3rd gen. It has so much low end and growl its amazing. Very very happy with it.