Just bought a 2008 GT need an exhaust?

I want to get the most horsepower out of my exhaust I want longtube headers with an off road x pipe, because I hear it makes more power than an h pipe, and a cat back. I just don't who to go with. Any suggestions for max power?

Are you going to be doing the install? If not, hit up Lethal Performance or Lamotta Performance.

Kooks, American Racing, etc all make good long tube headers. I really don't think you're going to see any hp difference between the O/R-X or H pipe. I'd go with what you'd like as far as sound. Just remember that it's going to be loud as hell with long tubes and an offroad mid pipe. I've got Magnaflow Magnapacks welded up as a mid muffler system. I'd highly recommend going with a bullet style muffler in a mid muffler design. If you don't want to do that you could just dish out the money for the actual cat back kit from Magnaflow. Either way it'll work, sound good, and put down some more power.

Thanks

If you just bought the car and it's all stock I would suggest starting out small. For example, just get an axle back to change up the tone a bit...these cars are different then previous generations in that if you ask people here I bet more than half have had more than one exhaust set up because theres a different sound with the mufflers in the rear plus there is so much available out there that its good to do some research on the sound/volume you will be happy with.

i am thinking about going with a FLow through style muffler, right now Bassani is atop my list for price and sound quality, But i won't know untill something is mounted on my car.

Yeah I have been listening to some of the exhaust setups and this is what I am thinking, kooks longtube header and kooks off road x pipe, and either Magnaflow magna packs cat backs or Mac boom tubes.

Boom tubes with that setup probably won't sound very good, IMO.

I have kooks longtubes and off road x with a bullet style blow through muffler, it was obnoxiously loud lol. So i had some pypes highflow cats welded in and I love the sound, still loud but more richer and mean sounding.

Well I checked it out on you tube and I thought it sounded pretty awesome but it was coming through some cheap speakers. But overall I thought it sounded pretty mean and that is what I want. Am I correct in that assumption?

With longtubes and any o/r mid pipe a straight thru muffler might be too loud. If you plan on doing L/Ts and an o/r mid pipe, I would either stick to stock axlebacks or one of the following: magnaflows, JBA, or GTAs.

That'll be very, very lound, indeed. You'll probably get a lot of that raspy sound as well.

And as far as power gains go for LT headers, the bang for your buck is very poor.

Well the last thing I want is a raspy sound on my mustang. I want my car to sound like an old muscle car with the extra power I would get from a full length exhaust.

Nothing you do is going to make it sound like an old muscle car, IMO.

Instead of an O/R X, I would install an O/R prochamber.

I thought they weren't making those any more.

They still make them. I believe they stopped making the catted prochamber. Here is link to the prochamber that will fit L/T.s
MAC Prochamber Pipe 2.5 inch no Cats

That's right.