http://www.bbkperformance.com/produ...ull-length-headers/96-04-ford-mustang-46l-gt-and-cobra-full-length-headers.html

They have different part numbers.

 

I know that they have different part number, but I do know of a person who did a C head swap and his B heads cobra and still use the same mac header may he got luck but I wanna know for sure since I found a good deal on some bassanis. Thanks

 

Yes they fit fine. They physically bolt up and work perfectly. But they will not be emissions legal.

The main difference is the 96 - 98 have 2 front EGR bungs and 1 rear bung on them where the 99 - 04 only have the single rear EGR bung.

I swapped a 96 Cobra engine into my 96 GT and deleted the front half of the EGR and used 99 - 04 BBK headers. I live in Fla and we have no emissions testing here so it was of no consequence.
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This is the engine I dropped in my car. If you look at the front of the exhaust manifolds you can see where the EGR tube comes out. There is one on the front of each manifold. 99 - 04 cars do not have this.

These are the 99 - 04 BBK headers I used. They just have the single rear EGR bung.

Here are the headers installed on the engine. The stock rear EGR tube bolts on perfectly.

96 - 98 long tubes on a 99 - 04 car can still be emissions legal if you plug off the front EGR connections. But 99 - 04 tubes would not be legal on 96 - 98 cars.

Hurst

 

Cool, Thanks.

So all I need to get is a 99/04 ERG tube and it bolts right up to the 96/98 intake?

 

Cool, Thanks.

So all I need to get is a 99/04 ERG tube and it bolts right up?

The stock 96 - 98 rear EGR tube will bolt directly to the rear bung on 99 - 04 headers. They are the same.

Or you can choose to perform an EGR delete to the intake and just cap off the EGR port on the tube.

Hurst

 

The front fittings on the exhaust manifolds are actually SAI (Secondary Air Injection) fittings, not EGR.

 

Correct me if I am wrong but the 96-98 and the 99/01 and the 03-04 heads all have slightly different exhaust ports.

While they will bolt up correctly the ports will not match and can hinder flow.

 

True, but not a lot.
Still better than logs.
03-04 specific headers usually cost a lot more,
so is it worth it for 1 or 2 HP?