Yes it's true, bought new set of GT take-off mufflers on Ebay ($85), the driver's side hanger bracket kit from Pypes ($65), 90 degree 2 1/4' OD exhaust elbow from Napa ($9.00), plus thread tap (5.00).
Since the majority of horsepower gains on the 4.0 V-6 are achieved with the single GT muffler installation (only 2 more HP added with second pipe) why spend the extra $300-400 for the H/X pipe, 2nd cat back pipe, shop labor, etc.?
The "fake/pho" second muffler installation is simple (1 hr.): Thread tap the appropriate hanger bracket frame hole inserts; measure, mark and cut bumper outlet hole (box knife with fine sand paper); install 90 degree elbow at appropriate angle to use as an anchor to the cross brace, clap and you're finished.
Okay, Okay, call me a poser, whatever! Took the car to our season opener car show last weekend and not one Mustang buff questioned it as fake. Can't tell until you're on your belly looking under the door. Even when running it sounds like duals, only time you can tell is at start-up when vapor exits the r/h side. So, if you want the dual look, and the throaty sound of performance exhaust, for only $164, give it a try. You can always hook it up all the way later on... I know some of you reading this will do it, but just wouldn't admit it!!!:bigthumbsup