My car is bone stock and the first thing I am going to do is a full exhaust. Is the H or X a better buy for a 86gt 5.0? Shortys, equal, or long tube headers? Ground clearence is an issue. And which mufflers should i buy for the cost. Also which size for the pipes and headers is the best?
Supposedly X pipes make a little more power. I think the main choice is sound and the only real way to tell what you like better is to listen to a couple of each. In my opinion nothing beats long tubes as far as headers go. They sound the best and give the best performance increase. They give way better low-end torque. They are a little harder to install but I think that is situational. Some people have no problem with them while some people have huge problems with the shorties. I have heard good things about the dynomax and magnaflow mufflers. I have flowmasters and they sound nice but supposedly don’t provide the biggest performance increase. I would go with 2.5 on the mufflers and tailpipes and 1 5/8s long tubes on the headers.
Keep in mind this is all my opinion from doing my own research and reading.
I have a MAC system w/ H pipe and equal lenght shorties, and 3" cat back. sounds sweet, and the headers really help the car breathe. ground clearance shouldn't be an issue w/ good exhuast system. My Mac system tucks up in the car real nice.
if your looking to squeeze every pony out of her go with the X-pipe, they make more horsepower, thats proven. not much mind you but they do make more. otherwise it like what rvogster said above, a matter of sound, which would you like better, the H has more of a 60's muscle car rumble, the X sounds a little more high pitched. as far as headers i gotta go with the longtubes as well. but if you decide to go shortys you have two options the "equal" lengths and the "unequal" lengths. the unequals are easier to install and make more power on the lower end and the equal lengths make more power higher in the powerband.
his car is bone stock, you guys think long tubes?? i would recommend unequal shorties and mac prochamber H pipe or Dr. Gas x pipe with what ever cat back you like the sound of, dynomax is good, flowmaster too
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'94 GT (5 speed) Convertible (White ext. white top, saddle int)
Flowmasters, Off Road H-pipe, 1-5/8" Mac Equal Length Headers, BBK cold air, King Cobra Clutch, Hurst Billet Plus Shifter, Mac White Face Gauges, ACCEL Coil, BBK Adj. Cable and Alum. Quadrant, Underdrive Pullies-- 245/50ZR16 Toyo Proxes FZ4's, Eibach Pro Kit Coil Springs, KYB Gas-A-Just Shocks, KYB GR-2 Struts, Rear Seat Delete--
Long tubes will still help with lowend torque even on the stock engine. It might not be quite as noticable but as he stated, full exhaust is the first thing he wants to do. If he decided to do heads, cam and intake later on he wont have to spend money on 2 sets of headers. Personally I will never go with anything but long tubes again. Shorties just cant beat them in power or sound. Good luck with whatever you decide.
you can go to www.mustangexhaust.com/sounds and listen to some clips of different setups. Or you can just go find a buddy with them on his car and listen/drive to see or feel the difference. just tryin to help
H or X pipe and which headers 
