I have installed the Bassani Stainless Catted X-pipe and
Magnaflow (not packs) catback exhaust. I absolutely love this setup. It sounds close to stock while idleing, but when you you get on this baby she roars like a lion. Also there is absolutely no drone in the car at any speed.
On March 6 here in Atlanta, we had the first SouthEast Mach1 Meet at Team Ford in Marietta, GA. There we were able to dyno our Mach's. The stock Mach1's with the auto's averaged 255hp 285lb/ft at the rear wheels.
The stock 5 speeds averaged 265hp 290lb/ft at the rear wheels. A drop in
K&N filter was good for 6hp & 2 lb/ft at the wheels for both the auto's and the 5 speeds.
At the time I dynoed mine I had the following mods:
K&N Performance Gold Oil Filter
Mobile1 0W/20 Synthetic
K&N Drop in Air filter
MagnaFlow Stainless Catback
my dyno numbers were: 292Hp 317lb/ft at the rear wheels.
I would have to say that the catback was well worth the money. I plan on dynoing it again soon. I estimate that the Xpipe was good for about 15 more hp. I will post the results as soon as I have them.