{FOX PARTS}headers

[91mercruiser]

does anyone know what headers will fit a 91 marquis and where to find them? thanks

[Pirate]

Most of your Mustang 5.0 (both stock and aftermarket) shorty headers fit...but they require the Mustang H-pipe....the Marquis manifolds have the O2 sensor bungs in them, and they are in the H-pipe on the mustang exhaust...

[Grand Marquis GT]

I saw you lookin!

Welcome to GMN!

Either stock or aftermarket mustang shorties will work. But you will have to modify the downpipes, because they are different. You have dual exhaust, I take it.

Heres is a pic of the difference in the collectors, the shorties are on the top, manifolds on the bottom. (Thanks for the pic, justin!)

[Pirate]

I saw you lookin!

Welcome to GMN!

Either stock or aftermarket mustang shorties will work. But you will have to modify the downpipes, because they are different. You have dual exhaust, I take it.

Heres is a pic of the difference in the collectors, the shorties are on the top, manifolds on the bottom. (Thanks for the pic, justin!)

And if you look close enough, you will see the face of Satan in the bottom manifold pipe opening...

[Grand Marquis GT]

Holy shit, I didnt notice that before! :hairrais:

[91mercruiser]

thanks for the help. theres not alot of places to go for info for these kinda cars. not alot of people like these type of cars.

[Pirate]

thanks for the help. theres not alot of places to go for info for these kinda cars. not alot of people like these type of cars.

Well, there is a plethora of information here...

[Grand Marquis GT]

Thanks

Yes we are the resident grand marq nuts

[phayzer5]

so do my exhaust manifolds = $26,000 grilled cheese?

[monterey1962]

A few questions:

1. So, both Mustang 5.0 stock and H.O. headers match up to the H-pipe? There was only one type/shape of H-pipe available? I assume w/cats and w/o cats were the same shape/bend.

2. Do the mustang headers bolt up to the stock GM heads? Does it make a difference in performance without the H.O. heads?

3. I'm going to be looking at a cat-less H-pipe on Friday. Does it make a difference if the Mustang had a manual or automatic trans? I'm assuming not, but I want to make sure there is no difference in the shape or bend of the H-pipe.

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Justin

[Ifixyawata]

1. Yes, Catted or Cat-less H-pipes are the same bend. X-pipes are usually more tricky.

2. Yes, they bolt up to standard (s.o.) heads. They still flow better than stock manifolds. You'll notice more top-end power as well as a better sound than with manifolds.

3. H-pipes are usually for AOD's and X's, as I said, are usually for 5-speeds. Some have reported getting X's to work around AOD's but the H is the safest bet.

[monterey1962]

Thanks.

------------------
Justin

[Lincolnmania]

if you are installing headers, i would get a set of aftermarket 1 5/8" unequal length shorty headers for a 86-93 mustang. the stock shorty headers are somewhat restrictive.
if looking for a low cost option, pick up a set of tubular manifolds from a 1990 lincoln towncar.........they are only found on the 90 btw they are a direct fit and should offer a slight gain in flow
oh and welcome to gmn!
scott