Aftermarket headers for 67 GT500

[rbarkley]

I went with FPA and MagnFlow 2.5 w/Tru-X.   However, I did not like how the exhaust system hung with the Tru-X, so removed it.
Had to add some 304 stainless and had the system TIG welded.   Looks good, tucks nice and sounds great.
Ron

[Side-Oilers]

^^^Same system on my KR.   Like yours, it took some modification/custom work to get it to tuck up properly, but I like the result...and the sound.

The bottom of the bellhousing is closer to the ground than the headers at the collector. 

[2112]

Nice and sanitary. I bet it sounds good too.

[Wedgeman]

Doug, I have known Stan Johnson ( FPA ) for over 45 yrs....I would say your assessment of him is spot on !   

[The Going Thing]

Doug, I guess the 1.76 exhaust valve was justified with the new engine so the Hookers breath correctly. <snicker>  I had never heard that correlation between primary tube and exhaust valve size before.  I can't find the flow sheet from the my Edelbrocks that Keith Black ported, but I think the flow on the exhaust side was in the 220 CFM range. 
There was a trade off Vs. the C6AE-R heads I had on the 428. Even with bowl clean up, unshrouding  and the 2.09 1.65 CJ valve the heads had more port velocity on the lower end of the RPM range. 
The ported Edelbrock heads seem to run in the 3200-6000 rpm range so it moved the torque band. In some respects it keeps one from smoking the tires every time you accelerate too hard in the first two gears.

Wow, you must have had a very close relationship with Keith Black to get him to port aluminum Edelbrock FE heads, tell us about how you managed to get that done?

Keith? I thought he said Clint? Sorry, my hearing isn't what it used to be. What? Did you say something? Open side pipes, you know?

It's just short of impossible to get Keith Black to port FE Edelbrock aluminum heads, especially since he was dead before the heads were ever made. Just digging the guy up, and bringing him back to life must have been a ton of work, then to be able to convince him to port heads - WOW !

You really are an idiot. Keith Black Racing Engines did the porting work. Keith Black has been dead for the better part of 30 years. However, the business was ran by his son for some time.  You can return to your regularly scheduled wife and dog beatings while attempting to make your miserable existence tolerable with daily over-indulgences in alcohol.

[shelbydoug]

I don't drink, but there is always time to start. It would explain why I see dead guys all the time. I ignore them though. They don't know nothin'. They're dead for a reason. 

[Royce Peterson]

When we placed the order the headers and H pipe shipped the same day. If you get the headers you will want the H pipe - it uses modern style ball connections with no gaskets. Very high end system compared to the old style junk.

For some reason they are not listed on the JBA website but if you call them you can place the order.

Last year I installed a set of JBA shorty headers on a GT500 convertible with a stroked 427. Compared to FPA the difference was night and day. The JBA headers are perfectly fitted. They are stainless so no coating is needed. The H pipe from JBA is also a masterpiece of fit and finish. They also offer an X pipe if you prefer. Outstanding product. Cleared the power steering with no drop bracket needed.

Now that sounds like a header to check into . I was not aware that JBA offered ready built FE headers for for 67-70 Mustang/Shelby.

[vtgt500]

With advancement in aftermarket, cylinder head options well designed headers have become more critical.  Unfortunately, reliable, published dyno tests are lacking.  On my build struggle with choices.  Budget dictated a 3rd set of soon to be asphalt assaulted, SuperComps.  Would be interested in first hand feedback on Kooks and Stainless Works products.

[427hunter]

Doug, I guess the 1.76 exhaust valve was justified with the new engine so the Hookers breath correctly. <snicker>  I had never heard that correlation between primary tube and exhaust valve size before.  I can't find the flow sheet from the my Edelbrocks that Keith Black ported, but I think the flow on the exhaust side was in the 220 CFM range. 
There was a trade off Vs. the C6AE-R heads I had on the 428. Even with bowl clean up, unshrouding  and the 2.09 1.65 CJ valve the heads had more port velocity on the lower end of the RPM range. 
The ported Edelbrock heads seem to run in the 3200-6000 rpm range so it moved the torque band. In some respects it keeps one from smoking the tires every time you accelerate too hard in the first two gears.

Wow, you must have had a very close relationship with Keith Black to get him to port aluminum Edelbrock FE heads, tell us about how you managed to get that done?

Keith? I thought he said Clint? Sorry, my hearing isn't what it used to be. What? Did you say something? Open side pipes, you know?

It's just short of impossible to get Keith Black to port FE Edelbrock aluminum heads, especially since he was dead before the heads were ever made. Just digging the guy up, and bringing him back to life must have been a ton of work, then to be able to convince him to port heads - WOW !

You really are an idiot. Keith Black Racing Engines did the porting work. Keith Black has been dead for the better part of 30 years. However, the business was ran by his son for some time.  You can return to your regularly scheduled wife and dog beatings while attempting to make your miserable existence tolerable with daily over-indulgences in alcohol.

I'll give Ken a call and ask him about your port work, the old man used to say an FE was only good for a boat anchor. When did you have the port work done? I can get you a copy of the flow sheet, they keep all those records.

[shelbydoug]

With advancement in aftermarket, cylinder head options well designed headers have become more critical.  Unfortunately, reliable, published dyno tests are lacking.  On my build struggle with choices.  Budget dictated a 3rd set of soon to be asphalt assaulted, SuperComps.  Would be interested in first hand feedback on Kooks and Stainless Works products.

I can't recall EVER seeing a dyno test just for headers but that could go a long way to illustrating the value of various exhaust modifications and improvements?

Must dyno pulls I've read use the shops "dyno headers". God knows what kind of trash those things are?


When I was looking for SB heads, I came across a comparison test of heads. The problem was that the 9th graders who did it used a cam that was not complimentary to the flow of the heads. So there wasn't much point to the entire thing.

Going from 180 intake flow on iron heads to 300 on aluminum heads showed no improvements in power. It was basically an RV type cam they tested with.

Dummer then dirt.


In the "old days", 427 Cobras came with these Thunderbird cast iron exhaust manifolds.
The thought at the time was that S/C type exhausts were worth something like 100hp.

That might have been the conclusion after drinking a six pack of Piels shorties? I'm not sure? Needless to say, tube headers help quite a bit.


The thing now in the digital age where beer doesn't help the dyno, everything is tunable.

You should consider though that by playing with the header configurations in attempts to maximize power, you need to constantly match cam profiles and inductions.


On EFI cars, guys spend maybe thousands of dollars to get the last 10hp out of the engine.

On a big block Mustang, good luck with that.


Before I went to the Super Comps, I'd try Doug's 180s. Either way you need to remove the power steering.

The Doug's are big tube and cross over behind the oil pan drop. Much more streetable then the Hooker's which are really for the drag strip with wheel stand starts.

[pbf777]

Before I went to the Super Comps, I'd try Doug's 180s.

The Doug's are big tube and cross over behind the oil pan drop.

     Not to quibble, but the Doug's cylinder #4 & #8 crossover header really isn't a true 180° header; but it's still a good product.           

     Scott.

[shelbydoug]

Before I went to the Super Comps, I'd try Doug's 180s.

The Doug's are big tube and cross over behind the oil pan drop.

     Not to quibble, but the Doug's cylinder #4 & #8 crossover header really isn't a true 180° header; but it's still a good product.           

     Scott.

The only thing with 180's is that they TEND to be tuned for one rpm peak.

I have that with my Pantera and as it works out 6,500 seems to be the peak?

With a big cube engine, I don't know where you are at with peak? It might work out since I'd suspect that with something like 468 cubes at 7,500 rpm, you might need to go to a full tube chassis to keep this thing from shaking itself apart in short order?


Again, it would be nice to see the specific "Mustang" BB headers tested on a dyno to help make the decision. Is it worth an extra $5,000, to get another 25 hp out of the exhausts?


I'd wager that the gorilla knuckles are probably as extreme as you might practically want to go? You won't need power steering because you won't be going around any corners anyway.

[pbf777]

I'd wager that the gorilla knuckles are probably as extreme as you might practically want to go? You won't need power steering because you won't be going around any corners anyway.

     True......... but this should be because the front tires are in the air!       

     And if one is stuck driving "around town", with your fat front tired (we had F60's), over-weighted big block monster with no power assisted steering, you learn to lean on the steering wheel hard, and let out the clutch, and the wheel turns!         

     Aaaah...........the fun!

     Scott.

[shelbydoug]

I'd wager that the gorilla knuckles are probably as extreme as you might practically want to go? You won't need power steering because you won't be going around any corners anyway.

     True......... but this should be because the front tires are in the air!       

     And if one is stuck driving "around town", with your fat front tired (we had F60's), over-weighted big block monster with no power assisted steering, you learn to lean on the steering wheel hard, and let out the clutch, and the wheel turns!         

     Aaaah...........the fun!

     Scott.

I live on a mountain. The road has no guardrails.

The Mounties take a dim view of wheelie bars.

[pbf777]

I live on a mountain. The road has no guardrails.

The Mounties take a dim view of wheelie bars.

    In the past when I rode my KZ1000 & CB1100F (rather aggressively) on the Blue Ridge Parkway, I was amused by the "guardrail" along the drops; these consisting of a long length of four-by-four lumber laying horizontal stacked upon a short piece positioned at the joints below thereby providing a approximately a twelve inch height. This appearing  just sufficient to provide some pitch if you engaged it so as to be sure you to acquire some air so as to clear edge of the crevasse ensuring a long tumble down.         

    Oh, and "Wheelie-Bars" are for little girls!           

    Scott.