Mustang and Ford Performance Forums banner
1 - 15 of 15 Posts

·
Registered
Joined
·
177 Posts
They are different...

Nav has exh ports just like all other Cobra heads = Oval shaped , but intake ports are huge.

GT500 has exh ports like the 03 Cobra/FordGT = More squared off shape
 

·
Registered
Joined
·
177 Posts
So Ford changed the exhaust ports on 03-04 cobras?
Yes, also some revisions were made to the exh port divider for improved coolant flow due to forced induction.

I am surprised there have not been more responses, there are a lot of people on here that know more about it than I do.
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #5 ·
Ok that makes since. What heads are you running and what headers? I really want to be able to use longtubes that's why i was asking about the exhaust ports on the gt500. I figured even if they weren't perfect fit they would be the easiest to modify.
 

·
Registered
Joined
·
1,622 Posts
The manifold bolt pattern is a also bit different on the FGT/Shelby head
than the Navi head.
The "father" of the FGT head, the 2000 Cobra "R" head,
has the exhaust bolt pattern like a standard Cobra/Navi.
 

·
Registered
Joined
·
177 Posts
I am using Nav heads with 98 Cobra exhaust manifolds. I have a set of stock GT500 manifolds hanging on my shop wall for a future project.

Long tubes would be nice, but I am happy with the performance of my 5.4 with the cobra manifolds for now.
 

·
Registered
Joined
·
1,622 Posts
I am using Nav heads with 98 Cobra exhaust manifolds. I have a set of stock GT500 manifolds hanging on my shop wall for a future project.

Long tubes would be nice, but I am happy with the performance of my 5.4 with the cobra manifolds for now.
Same combination Al used way back when.
5.4's rock.
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #9 · (Edited)
The manifold bolt pattern is a also bit different on the FGT/Shelby head
than the Navi head.
The "father" of the FGT head, the 2000 Cobra "R" head,
has the exhaust bolt pattern like a standard Cobra/Navi.
So 2000 Cobra "R" heads are the same as the Cobra/Navi exhaust bolt pattern? Just trying to clarify.

Also couldn't you just buy the GT500 headers and a set of regular cobra headers, then have an exhaust shop put the cobra flange on the gt500 headers? I know it wouldn't be the cheapest route. But if it would work IMO i think it would be worth it.
 

·
Registered
Joined
·
52 Posts
The GT500/FGT exh port is not the same as a Navi or Cobra. The ports are close but the bolt pattern is wayyyyyy off.
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #11 ·
The GT500/FGT exh port is not the same as a Navi or Cobra. The ports are close but the bolt pattern is wayyyyyy off.
I understand that i'm talking about cutting off the actual exhaust flange that mounts the headers then welding up a flange off of a set of cobra headers that fits.
 

·
Registered
Joined
·
1,622 Posts
I understand that i'm talking about cutting off the actual exhaust flange that mounts the headers then welding up a flange off of a set of cobra headers that fits.
Some header mfrs will make you a set with the flange you want.
 

·
Registered
Joined
·
49 Posts
Even if you cant find a set with the right flange you still would not have to buy 2 sets of headers you can buy just the exhaust flange. A lot of places sell them for custom header builds.
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #15 ·
I was trying to find a place that sells build your own header kits but couldn't find any. I have a few people in my family that are really good at welding and build classic cars so i know they would help me.
 
1 - 15 of 15 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top