85 gt header size

green

New Member

Apr 26, 2003

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Dec 18, 2004

#1

• Dec 18, 2004

• #1

had a question about my 85 gt. it has stock heads E5TE,s. i was wondering what size headers fit on these heads. are they 1,1/2 or 1,5/8 . reason i ask is because when i got my car it only had a fake dual exaust system. so i bought a h pipe off a 88 gt, put the h pipe on my car but they wouldent fit on my stock headers, so i got the headers off the same 88gt bolted them on and it worked good. but if my heads are 1,1/2 how come the 1,5/8 bolted up to my stock heads without any probs. thanks

 

Michael Yount

Mustang Master

Apr 10, 2002

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Charlotte, NC

Dec 18, 2004

#2

• Dec 18, 2004

• #2

You're thinking about it too much. Clearly the headers off the 88 bolted on and worked - so you're ok. The stock headers have primary tubes that are even smaller than 1.5" - more like 1.43". Were they stock HO headers on the 88, or aftermarket? What would really help is if you could score a different set of heads for yours...

 

green

New Member

Apr 26, 2003

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Dec 18, 2004

#3

• Dec 18, 2004

• #3

ya they were stock headers off the 88 gt. problem is i dont think they make headers with 1.5 inch primaries. so if those headers off the 88gt are 1,5/8 how come they worked on my car, u would think they would leak like crazy. so does this mean i can go buy a set of say bbk equal lenth headers that are 1,5/8 and they will bolt up to my heads with no probs either?

 

Michael Yount

Mustang Master

Apr 10, 2002

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79

Charlotte, NC

Dec 18, 2004

#4

• Dec 18, 2004

• #4

As I mentioned before, the stock headers are no where near 1 5/8" primaries; they are less than 1.5". If yours have 1 5/8" primaries, then they are not stock.

I don't understand your question though. The head surface is flat, and the flange is flat. As long as you've got a good gasket, the primary size of the header doesn't have to match the size of the exhaust port in order to seal. Hardly anyone's header primary tubes are a perfect match for their exhaust port size. ?????

 

green

New Member

Apr 26, 2003

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Dec 18, 2004

#5

• Dec 18, 2004

• #5

ya i suppose it would still seal good but i thought all of the E7TE heads had 1,5/8 primaries.

 

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

43,179

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Massachusetts

Dec 18, 2004

#6

• Dec 18, 2004

• #6

85 headers and 86+ headers are the same. The only difference is one of the headers on the '85 has a flapper valve in the collector. The opposite header is basically the same as the 86+ headers.

The only difference between E5 heads and E7 heads is the combustion chamber size. The E7's have a higher compression ratio.

As far as the exhaust ports on your e5 heads...same thing.

You are thinking way too much about this. The 88 headers will work fine. They will bolt up like they were supposed to be there from the factory.

 

green

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Apr 26, 2003

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Dec 18, 2004

#7

• Dec 18, 2004

• #7

ya i have had them on my car for a while now and they work good. so what would be the point of buying aftermarket headers then? there would be none. if i bought bbk headers or hooker headers etc... it would be wasteing my money right. because i am not going to get the gases out any better with them than i would with the stockers. i mean the primaries might be bigger but they will be useless because the extra space on the header will be covered by my heads.

 

maverick0716

Founding Member

Jan 12, 2002

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Chilliwack, BC, Canada

Dec 18, 2004

#8

• Dec 18, 2004

• #8

You're actually quite right. On a stock engine, going with a bigger header isn't going to give you anything. If you are going to keep your car stock, get a GOOD mandrel bent header (1 1/2") and call it a day. Most people just put on 1 5/8" headers because it gives the engine room to grow.....and it seems they're easier to find.