After much thought, the exhaust for the car came together really well.  It started with V8 Archie's advice to get the Sanderson CC-90 headers.  The main reason is that these headers are designed for transverse, V8 Fiero conversion.  It allows the exhaust to clear the right axle perfectly.  Also, Archie's bracket for the alternator that mounts on the left side of the motor will only work with these headers.  As far as headers go, be sure and match your ports on the head with the header.  The ZZ4 has "D" ports and other heads have "oval" ports.  Also, I'm debating on going with ceramic coating or exhaust wrap.  It's important to reduce the heat in the engine compartment as much as possible.  The ceramic coating is more effective but a lot more costly.  The headers won't be seen in the engine compartment, so chrome headers will have no esthetic appeal. 

I spent countless hours researching how to fabricate an exhaust system where the muffler and catalytic converters that needed to be installed in a very compact space.  I ended up going with Flowmaster's Series 80 muffler with twin compact catalytic converters.  I purchased a bunch of 2 1/2" galvanized steal, mandrel U-joints from Summit Racing.  From the front exhaust is routed under the car in the same location as the Fiero exhaust.  The joint under the car is connected with flexible exhaust pipe.  The rear header is also connected to a catalytic converter with flexible pipe.  The purpose of that is the reduce the amount of stress on the exhaust system as the motor twists during times of high torque.  From the converters, the exhaust is routed to the muffler and out through the bottom of the car.  Fittings are placed at four different areas of the exhaust system so the entire system can be removed from the car for servicing.

7/12/09:  Over the past couple of months I've been considering redesigning a large portion of my exhaust system above.  Sam at Century Performance was a great help.  First off, he set me up with D-port, ceramic coated, CC90 Sanderson headers.  Since I may upgrade the ZZ4 to over 400+ HP someday, he strongly suggested I move up to the 1 5/8" primaries.  Then, we started talking about muffler options.  He convinced me to drop the catalytic converters and Flowmaster muffler and go with a Borla exhaust.  The Flowmaster is just too deep and throaty for a Lambo clone.  So, I've spent the last two months researching and comparing exhaust sounds of different systems and brands.  I've decided to do an experiment of my own.  Check out the sounds below of different configurations. 

8/23/09:  I decided to redesign the exhaust system in hopes of getting a less muscle car like sound.  The exhaust pipes that come off the headers merge to 3" from 2 1/2".  I tied to make each side equal length before the merge to get the same blend of exhaust.  Next, I installed a heat shield right below the oil pan.  I'm sure I will need to make another heat shield around the muffler after I mount the body.  I also installed flexible exhaust pieces on both sides of the headers.  This is so the engine can flex without putting strain on the headers.  The muffler is a 12" XR-1 Borla Sportsman racing muffler.  After the body is mounted and the bumper attached, I will then fabricate the tail pipes.  At this time, I capped one of the exhaust openings.  The thought is that one working exhaust pipe will produce a smoother, higher pitched sound.  I plan to test it once I get the tips installed.  Take a listen below.  I believe the extra work and money will be worth it.  I would have rather installed a 180 degree header system.  That delivers a great sounding V8.  I doubt I would have the room in this setup, so this will have to do.