Fox T-Bird/Cougar Forums  

Hey Charlie...a lot of guys are grabbing the Mustang 5.0 stock shorty headers, and from there an aftermarket X or H pipe (I went with a catless BBK X pipe, in 2.5") and whatever cat-back kit you want. Keep in mind though, that while pretty much every X and H pipe for a Fox Stang will work great, the rest of the exhaust for the Fox Stang will need lengthened a few inches to fit our Birds/Cats, due to the longer wheelbase.

Now for the rest of the system I went with Flowmaster American Thunder, again in 2.5". I got mine for a '87-93 Stang LX 5.0, but you can also use the GT kits, as the tails are a little different because the GT Stangs had the effects, so the tails come out a bit different.

Any good exhaust shop would be able to lengthen the pipes for you, but if you live in a smog area, you'll need to stay with a catted X/H pipe, instead of the offroad version. Obviously the catted part is a heck of a lot more....if you're only looking for lers, but don't know what to get, there's tons of vids on you tube of different exhaust setups. Myself, I decided on flowmasters because of cost, and that's what a friend has on his '95 5.0 Stang, and I think his sounds awesome. Throaty, decent tone at idle, and it doesn't scream like a glasspack when you lay into it. Magnaflow is pretty nice too, but a bit costly, and a little louder.

Thunderjet302 has a nice exhaust on his car, but of course he has a nicely cammed engine, so that affects the idle and the volume a good bit.

The stock cats are restrictive that is a given. So i am going to say with a dual setup with the x you posted and say a 2" exhaust all the way back with stock manifolds . I would suspect 8-10 HP . That is from experience. The shorty headers dont really do much but better than the cast iron ones. I would suspect a set of shorties will increase your HP by maybe 2 HP over the stock setup. just a guess in my opinion. Figure on app 12-13HP with shorties and a 2" full dual exhaust past the rear axle.. Good luck!!

So you cannot find a 2-1/2" off road X-pipe or H-pipe that is used?  Common man, do some searching on the Mustang sites.

http://forums.corral.net/forums/exhaust-parts/1408628-87-95-bbk-catted-h-pipe.html

http://www.stangnet.com/mustang-forums/forums/fox-body-mustang-exhaust-for-sale.299/



Google forums in your area so you do not have to pay any shipping.  Dig man, dig.  Don't pass up on a Fox hatch car cat back as the tail pipes are not visible and can be lengthened.

Darren

There's so much stock stuff you can run for cheap.  87-93 is what you'll be looking for.  Mustang stock headers, 2 1/4 Mustang stock H, extended Mustang stock pipes and tails with some Mustang Magnaflows.  You'll want to look for an H from a car with AOD to get the best fit.  The lers will probably cost more than the whole rest of the system if you buy take-offs from Mustang guys on boards and swap meets.  $500, tops all together and you don't have to worry about whether not having cats will hurt you.  I'd estimate 15HP, which seems low, but that intake you're running and those heads and cam would be what's holding you back (in that order).  With an Explorer top end and an HO cam, your exhaust gains would be higher (I'd guess at least 25HP), but the E6 heads, non-HO intake and cam make it wheezy and all the exhaust in the world won't make it suck more air in than the top of the engine can flow.  Like Tom is fond of saying she's an air pump. 
Aside from that, I wouldn't waste time looking for an X, because until you're running high rpms and much more power, you're better off with a cheap and highly available H.  Spend less on an H instead of an X and be able to spend more on everything else.

If you're looking for power and you're only thinking about the exhaust, you're wasting your time.  And if THAT's the case, just go for a good sound.  Guys on the street won't know the difference.