# Best type of headers for a '68?



## '68er (Sep 16, 2009)

Does anybody have suggestions for the best type of headers to install on a '68 GTO and where to get them for a reasonable price? By best, I mean performance-wise. 

I have a 400 engine with tri-power carbs and new 3in flowmaster system I'm getting ready to put on. Any recommendations?

Thanks


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## Rukee (Feb 8, 2007)

I'd do a set of Doug's ceramic coated headers. :cheers


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## jetstang (Nov 5, 2008)

I just put the $200 Headmans on that are in summit. They were on top of my prop valve. Then, when I went to put it in drive I couldn't as the linkage to the column hit. I had heard they weren't the greatest, but can attest, they're not great. Now, the paint is already burning off, but that's expected. They do fit and did seal, so that is a plus.
I'd go with the Dougs as Rukee says, but $500 a set is steep..


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## '68er (Sep 16, 2009)

Ok, cool thanks. What is the difference between the 3 in collector versus the 3.5 in? Considering my flowmaster system is 3 in as well, does that make a difference? 

Doug's tube diameter is 1 7/8, is that the only size headers come in? 

Do you know if the 68 has round ports or D ports?

Thanks again.


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## jetstang (Nov 5, 2008)

Unless its' a ram air 4? it has D ports. 3.5 should be for o port heads. Big exhaust kills bottom end, but your choice. Smaller pipes fit better. Pipe size changes with collector size.

I just went on ebay and got Dougs V-10 Ford headers for $11.95 a set, I bought 10 sets!!! LoL. They go for $916 a set in Jegs, thanks Rukee for making me look to see. Here's the link:
Doug's Headers D6620 : eBay Motors (item 150436147154 end time May-21-10 14:21:55 PDT)
I think I'm going to get an email denying me, but what the hell, maybe they'll ship it without paying attention. Oh, I got free shipping also, lol..


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## '68er (Sep 16, 2009)

Hmmm.... That's interesting. You say a bigger pipe kills the low end. I thought air-flow was everything, which should include the low-end. Shucks, why are the 3 in flowmasters twice as many $'s as the 2.5's then? Would it be better to forget the headers and go to a 2.5 in flowmaster if low-end power is the goal (which it is)? Or go with the 2.5 in flowmaster along with headers? 

Pipe size changes with collector size, huh? To what? Does the exhaust pipe inch size need to be the same as the collector size or is it variable? This hobby is complicated if you don't know what you're doing.....


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## jetstang (Nov 5, 2008)

As you gain HP, you need to expand the exhaust. HP is all high end, torque is down low and is what you feel in your backside. The faster you get the air charge in and out of the motor down low the better throttle response and low end power. Smaller carbs, headers, cam and exhaust build low end power, unless they restrict power-too small. The bigger you go, the more top end HP you can make, and the bigger components you get. The biggest trick is matching all of your parts for the optimum torque and HP.
What is your combo now?
A 1 7/8 pipe will have a 3" collector, 2' for 3.5" ie. or something like that. Collectors vary with the size of the pipe.
I have been motorheading for years trying to figure all this out, and you can't, you just get better.
Nascar engines leave the pits burning the tires, because if they aren't turning 6,000 RPMs they'll stall. You couldn't drag race a NASCAR motor because they'll bog at the line, because all their components are for top end, no bottom end torque.


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## '68er (Sep 16, 2009)

Well, I basically have a stock 1968 400 engine with stock headers. I believe the exhaust sytem on it now is 2 in, which I'm going to replace (unless it's better for low-end with new headers). What would be the ideal sytem for this car to optimize the low-end torque? If you look at these links, they both suggest the 3 in exhaust as optimal. But is that for low-end power, which is what I'm shooting for? Anyone know for certain? Thanks

Magnaflow Technology

Exhaust Theory (under pipe sizing)


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## jetstang (Nov 5, 2008)

Adding headers over manifolds will pick up a few HP, and new mufflers and aluminized pipe looks better than old rusty pipe. 
This is from your article:
the best high-revving horsepower can be had with headers utilizing larger diameter, shorter primary tubes. Headers with smaller, longer primaries will get you slightly better fuel economy and better street driveability. 

I also read where it wants 3 to 3 1/2". That seams big to me, but they are talking max HP, not torque. I think dual 2.5 is fine, even 2.25. I would love a 3" exhaust, it looks good and sounds great, but is alot more expensive. That article also said that flowmasters are the worst flowing, so I think the article is probably biased, but good info. If you are going to spend the big money, make sure it has Mandrell bends, normal tubing benders crimp the pipe, thus taking your 3" to 2.5", while mandrell bends keep the 3" through the bends.


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## Rukee (Feb 8, 2007)

If you do the 3 1/2" headers, you can get a 3 1/2' to 3" collecter to bolt onto the 3 1/2" headers and then will bolt right up to your 3" exhaust. Dual 3" will be fine, I wouldn't want to go any bigger though without a big bore engine.


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## Rukee (Feb 8, 2007)

jetstang said:


> Adding headers over manifolds will pick up a few HP, and new mufflers and aluminized pipe looks better than old rusty pipe.
> This is from your article:
> the best high-revving horsepower can be had with headers utilizing larger diameter, shorter primary tubes. Headers with smaller, longer primaries will get you slightly better fuel economy and better street driveability.
> 
> I also read where it wants 3 to 3 1/2". That seams big to me, but they are talking max HP, not torque. I think dual 2.5 is fine, even 2.25. I would love a 3" exhaust, it looks good and sounds great, but is alot more expensive. *That article also said that flowmasters are the worst flowing, so I think the article is probably biased, but good info.* If you are going to spend the big money, make sure it has Mandrell bends, normal tubing benders crimp the pipe, thus taking your 3" to 2.5", while mandrell bends keep the 3" through the bends.


That's funny, cause I was told a 3" flowmaster muffler will flow more air then a 3 1/4" straight pipe.


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## '68er (Sep 16, 2009)

I'd still like to know the best setup for low-end torque? I thought there'd be some way-cool goat type dude straight out of the 60's who'd be like, "Yadda-yadda-yadda, this is the waay to go!" Only been 42 years since '68 :lol:

1 7/8in, 2.5in, 3in
2 in, 2.5in, 3in, 3.5in


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## jetstang (Nov 5, 2008)

'68er said:


> I'd still like to know the best setup for low-end torque? I thought there'd be some way-cool goat type dude straight out of the 60's who'd be like, "Yadda-yadda-yadda, this is the waay to go!" Only been 42 years since '68 :lol:
> 1 7/8in, 2.5in, 3in
> 2 in, 2.5in, 3in, 3.5in


Oh, you want the 60's setup.. Headers and header glass packs dumping at the tranny cross member. In the 60's everybody went for HP, not torque, so 3.90 gears or 4.11's, 3500 stall, max RPM and slicks. But the speedlimit was lower and you weren't doing 80 on the interstate. It says 1 3/4 or 1 7/8 for D port heads, and 2" for round port ram air heads. Check Butler performance, they are making big power out of Poncho's. 1 3/4s are going to make more torque than 1 7/8 or 2's. Bigger isn't better, bigger is for HP and RPM, not torque.



Rukee said:


> That's funny, cause I was told a 3" flowmaster muffler will flow more air then a 3 1/4" straight pipe.


Rukee, no offense, that info was out of the article, not me. I like flowmasters and think they sound great.


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## khinton (Jun 22, 2008)

I would save the money and the hassle, keep the stock 400 manifolds and go with the 2 1/2 inch magnaflow stainles system -- works great for all around performance and sounds deep and great--it's the link on our forum--bet you will like it.:cheers (I tried flowmaster 40s and 50s --personally hated the sound of both)-- to much resonance and to high piched for me; each to there own


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## 646904GTO (Feb 10, 2008)

jetstang said:


> Adding headers over manifolds will pick up a few HP, and new mufflers and aluminized pipe looks better than old rusty pipe.
> This is from your article:
> the best high-revving horsepower can be had with headers utilizing larger diameter, shorter primary tubes. Headers with smaller, longer primaries will get you slightly better fuel economy and better street driveability.
> 
> I also read where it wants 3 to 3 1/2". That seams big to me, but they are talking max HP, not torque. I think dual 2.5 is fine, even 2.25. I would love a 3" exhaust, it looks good and sounds great, but is alot more expensive. That article also said that flowmasters are the worst flowing, so I think the article is probably biased, but good info. If you are going to spend the big money, make sure it has Mandrell bends, normal tubing benders crimp the pipe, thus taking your 3" to 2.5", while mandrell bends keep the 3" through the bends.


They are correct. Flowmasters are very restrictive compared to REAL performance mufflers. If you want real top end power the Flow-Tech or magna-flow or just about any other performance muffler has better dyno results, I know I dyno my cars and have proven it over and over. plus that every Chebby out there has the thud, thud, thud of flowmasters...Dare to be different.


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## jetstang (Nov 5, 2008)

646904GTO said:


> They are correct. Flowmasters are very restrictive compared to REAL performance mufflers. If you want real top end power the Flow-Tech or magna-flow or just about any other performance muffler has better dyno results, I know I dyno my cars and have proven it over and over. plus that every Chebby out there has the thud, thud, thud of flowmasters...Dare to be different.


I have chinese Flow Master rip off mufflers on my 454, and they sound good. I have stainless Edelbrock RPMs on my 70, they are real loud straight through design, but don't resonate. Dyno tells the tail.


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## PBF Bioset (Apr 25, 2010)

Hi,
as I read more torque on lower RPM is searched right?

I know a system, used by BMW for example, which is easy to realize. The main idea of this is to reduce the diameter of the exhaust system on lower circles per second.
They put on a double pipe on the R6 and installed a hatch at one pipe of the muffler that is controlled by underpressuere the engine produces behind the throttle body (similar to brakebooster).
In detail there's a membrane which pulls a lever that turns the hatch of 90 degrees on high RPM. (looks like a throttle body in the exhaust if you see a 325i E46) 

In a V8 I would think of mounting one hatch per cylinder bank and using a 4 in 1 haeders before the exhaust system is split again. The easiest way would be to install a Y-pipe and two small mufflers at the end. One with the installed hatch of cause and the other constantly open. 
The membrane should pull at the RPM where the A/F mixture turns to rich.


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## Rukee (Feb 8, 2007)

They are called electric cut outs.


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## PBF Bioset (Apr 25, 2010)

Rukee said:


> They are called electric cut outs.


Ha! Yes. It's the same ^^
But BMW built it without electric...or copied it...who knows :lol: 


Thanks for the info


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## '68er (Sep 16, 2009)

Guys, thanks for all of your help. You've put some ideas in my head which is a scary thought, especially if you knew me. 

Jetstang, you went above and beyond. Are you sure you're really not some dude straight out of the '60's? 

PBF, I would buy that system if it became available.

I'm going to join the dark side by returning the 3' Flowmasters and going with Doug's Headers and 2.5' Magnaflows. The dyno test results are the main reason for that. Cheers!


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## jetstang (Nov 5, 2008)

'68er said:


> Jetstang, you went above and beyond. Are you sure you're really not some dude straight out of the '60's?!


No, I'm stuck in the 80's, the days of Air Shocks, L60-15s, 8 tracks and smokey burnouts.. The days of the $500 rusted out and abused muscle car, and $50 junkyard big blocks.


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