The Question of Headers
 

Aftermarket headers are usually better than stock OEM. I've been looking for some Longtube headers for my 01 and though I've narrowed it down to Mac and Bbk, I still want input on what people think. Please, share with me your thoughts.

I have the BBK longtubes and Short-H on my '00 GT and I wouldn't wish them on anyone. The passenger side taps against the frame sometimes depending on what the engine torque is doing, the driver side rubs against my Borgesen steering shaft, and the collectors seem to be too far apart (probably why the headers rub) when you try to bolt the H-pipe up, resulting in an exhaust leak 3 out of 4 times that you try to bolt it up. The power gain was pretty impressive, but the quality seems to be crap.
I have heard way more quality problems with MAC than I ever have with BBK, so I would stay away from them also.
I noticed that Bassani, Hedman, and Hooker all make long tubes for 4.6s now, so you may want to look into those.
If you are planning on doing the intall yourself, it took me about 12 hours and a whole lot of cussing. The main problem is the passenger side - you have to jack the motor up about 3" and there is just no room to get your hands in around the 4 tubes to tighten the top rear bolts.

I'm sorta looking into Hooker LT headers. But I'm still trying to figure out if they make a custom short H pipe for it. :( None of the sites I've been to have said anything about it.

I've got the following setup
MAC longtubes
MAC short H-pipe with high flow cats
borla catback

I really love the entire setup. Been running this for about 10k miles. Could tell a large improvment with the headers and high flow cats. This is on a cobra but I'm sure a GT would see the same effect.

I've heard some good things about Hooker LT's. As far as headers go, LT's are the way to go.

I've read that the Hooker and JBA (I think) LT headers are closer to the chassis than the others, so the problem with clearance isnt' as bad. (eek!)

I'm still considering all the possibilities. But I like Bbk better than all, but don't like the price.

The BBK stuff isn't too good. Since they are a company that makes all kinds of parts for many different cars. The BBK exhaust components often leak and don't fit right. The best quality headers out there are by far Bassani. They are knida expensive but they are the best. MAC exhaust stuff is pretty good too.