Muffler/Exhaust Questions

I have a 84 GT CFI car. I really want to run duel's. but as most of you know on the pass side there is what appears to be a fuel pump. is there such a thing as a round muffler? and how good are they? does anyone think there is a easier way to do this?
-Aaron
 
Those are glasspacks. If you want your car to sound like a truck, go for it. I wouldn't get them. Cat's are not restrictive enough to cause any real diffrence. MAYBE 3-5 HP on your stock Mustang vs. not having them. They act as a muffler, and combined with the Magnaflows or Dynomax, it should be decently quiet.

Nick