I got the shop I bought my tuner from to tweak the stock tune one the mach. Over all hp/tq only went up a 5 or 6. But, he was able to get to the power band wider and get the power to come up sooner.
Kooks and SLP seem to be what alot of the guys on the registry like. Make sure your tranny is in good shape because some of them wont let you pull the it without having to take them off, and that would be teh suck.
Sometimes even with a high flow cat you will still get a CEL. I had have 2 mustangs that did it. Finally I gave up and went with an OR X and had the tuner switch off the rears when the shop did my gears and fixed the speedo.
www.gearheadsperformance.com - they did my gears and tune at a great price and turn around time. Travis the owner is a nice guy and took the time to make sure I got what I wanted not just sell me stuff.
Got weld in 40 flows with bassani o/r x here, had it for almost 2 years. Comes off in the morning for a bassani catback. I forgot exactly how much I liked the sound of the bassani stuff until I found an old vid of the GT I used to have. Can't wait to hear it on the Mach.
there were glasspacks on the mach when I bought it. they sounded fine on accel but deccel just drove me nuts. they had to go. too much crackling and popping.