Headers or manifolds

[GRX]

Originally Posted by HO455

#1 tip for headers is to verify the flange sealing rings are flat and true with each other. Most manufacturers send little or no time on this. I surface mine on a 3 foot belt sander so all of the surfaces contacting the gasket are on the same plane. If there are low spots I build them up with a bead of weld and resurface the flange. On the collector end I am a big fan of cuttng the rings and flanges off and using truck bands in their place. With some exhaust sealing paste under them for a leak free seal.
Just my system, your results may vary.

^^ this x1,000, plus one more. Uneven and roughly sawed off tubes sticking through a flange does not make for good sealing. Neither does a warped flange from production process. Trip on a large belt sander can do wonders.

As for manifolds, I am a fan of using them unless your build can make use of headers. Mag articles and their sponsors are good at convincing people they are guaranteed bolt on horse power. Majority of people buying headers are getting benefit of sound only.

[special-K]

So, do the center dump manifolds like Grumpy shows work in C/10 frames or not? 2.5" ramshorns are a slick way to go. I have a set of Sanderson block huggers the guy I bought them from said were fitted on his C/10. I'm not sure they will or not, but I have both 2wd and 4wd so I bought them.

Here's a little story from my 45 years experience with these trucks. I was only 13 building models 50 years ago in '68 . In '89 I had a dual exhaust system made up from the manifolds on my '71 Custom Camper. I always did headers since my first truck, a '72 I bought in '73. But this '71 was all original in fantastic condition as well as a very well optioned example. I still had to have my dual exhaust w/turbo mufflers, though.

So, with new dual exhaust, sounding real sweet, we head cross country to Taos, NM. Visited my sister and took a route up into CO, through 4-corners, and on across to the North Rim of Grande Canyon. Came back down the decent, into the flat, hit the gas (no throttle used on decent) and it sounded like pure hell. I look to find one manifold all exploded where it all collects. Hobbled it on down to Flagstaff sounding like an old farm tractor to a quality exhaust shop. Couldn't find any manifolds in the area and the only headers in town were El Cheapo crap. It hurt my feelings, but I had no choice but to have him use those, cut my fresh custom pipes, and dogleg them into the El Cheapos so we could continue on our way. I even had a set of Blackjack AK5000s in the box back home I decided not to use to retain the manifolds.

That truck got run all over the place on trips, as well as around the area with camper removed. I drove that truck till '04 with that same exhaust system I never had to touch. I did do heads and timing chain at one point, so gaskets at head got replaced once.

I have another manifold total failure story as well. I'm not dissing manifolds, and I could go either way these days. But, both options can have an issue same as anything on a vehicle. My experience has been no more with one than the other. But when it comes with dealing with the issues that may occur, I'll take headers any day. No one likes to deal with donut gaskets or issues with the studs, which are fairly common. When new, there are no issues with either.

[KQQL IT]

Originally Posted by RichardJ

>>GM (Chevrolet) has produced high horsepower, high performance engines for years......every single one....came from the factory with manifolds...<<

Close, but not 100%.
The C4 Corvette L98 TPI engine used these tube headers, covered with the heat shields. The following LT1/LT4 engine had nearly identical cast manifolds and curiously covered again with tin shields.
Some believe Chevy decided the tube headers added too much engine noise.

>>Headers leak when you overtighten fasteners.<<

I found this to be especially true on my inline six. With the more even tightening ability with studs the length of the head, new gasket leaks are generally resolved by loosening the nuts.

We had a federal emission 454 with tube headers too.

[Metaldoc]

I used my manifolds but ceramic sprayed and baked in a cheap used oven, headers are too expensive usually leak.

[special-K]

When the factory wants an engine to run exceptionally well they use tubular manifolds. The HD application 85/86 3/4t trucks that ran on regular leaded gas had true dual exhaust, no catalytic convertors and tubular manifolds...and ran really strong. So, which one is better, cast manifolds or tubular headers? The answer is tubular manifolds

But cast headers are super nice!

[collin70k/20]

As long as you buy good headers and good gaskets they are the way to go. I have headman mid lengths on my 1970 k/20. What ever you do, don’t get flowtedh headers no matter how much cheaper they are.

[special-K]

Flowedheck?

[CharlieBrown]

I have had my 72 since 1978....never put headers on it ...till now.I just did a complete frame off and I decided to do headers.I put a nice set of ceramic coated ones on but I only have a 100 miles on the truck so far.Man they sound great....don't know how many manifolds I changed over the years..broke several when the truck was a daily driver....now...car shows and fun only...time will tell.

[Keystone_Hate]

Watch this. Then decide for yourself.

https://www.youtube.com/watch?v=Y7_lSU3D0jw

[special-K]

He just about talks down the manifolds by being surprised they did so well. That's a performance design right there. Those are nice, pretty cool Hooker makes them. Those are headers as much as they are manifolds. That's what I call cast iron headers

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[54belair]

Save your money--On a bread and butter type engine, used in every day driving there is data proving that headers have no appreciable advantage. Cast iron manifolds will keep your engine bay cooler----But, headers will sound better!!!
In my case, I just finished a 5 yr total resto/rebuild---I have three sets of headers but went looking for a set of ram horns. Rams install easier and will outlast headers.

[dondb]

OK...don't want to brink up old arguments.....But......did you put gaskets in with the ram horns?

[Ironangel]

Headers...Wrap your header bolts in Teflon tape and they stay tight. Nascar trick...

[BRL]

Have had a set of some cheap auto parts store (Doug Thorley/Headman?) headers on my truck for 15+ years without any leaks, and I think it is because I cut the flange between the ports and used copper gaskets.

Heck, I even got an extra set of headers just in case, but haven't had to use them yet.

My engine is set way back on 6 cylinder brackets (still clears HEI) with no problems whatsoever.



I like the fact that headers are lighter than cast iron manifolds and IMHO...

...antlers look better than horns anyway!

[Sanduners]

First post here, just picked up a 68 GMC 3/4 with a crack in the right manifold. Looks like new manifolds after reading this post.

Originally Posted by heritage03

This is a great site and have learned much already, there is a lot of knowledge here!!

Agreed...

[BCOWANWHEELS]

Pros for headers, look cool

cons
they rust out quick
expensive
leak like crazy

[7 Devils]

Truth that outside of clearance issues long tube headers will easily outperform the ram horns in terms of flow. As others mentioned though, sealing and fitament can be problematic depending on the quality of the header you choose. Another question is how healthy is the small block your using? Does really need headers or do you prefer the look/sound?
For a DD, ram horns will provide for maintenance free operation. Good headers that fit nice and have good warp free mating flanges usually start in the neighborhood of $500 and up.
For me, DD general use is ram horns. Competition/show is headers. Just my .02¢

Dan

[Grumpy old man]

your driving a truck with the aerodynamics of a shoe box , a late model Subaru will blow you away . why does everyone think a set of headers will make any kind of difference over rams horn on a daily driver ?

[7 Devils]

My truck went 10.80's on the motor in street trim.
Just saying.

Dan

['68OrangeSunshine]

Originally Posted by Metaldoc

I used my manifolds but ceramic sprayed and baked in a cheap used oven, headers are too expensive usually leak.

I did the same process on some Hedman hedders about 12 years ago. I airbrushed-on some black ceramic stuff from Eastwood and baked them in my Mom's ex-Hotpoint oven. [After she got a new one.] 500* for 2 hours, IIRC.

I bought my Hedmans in 1999. for my then-new Mr Goodwrench 350 in a '71 K/1500 Jimmy. Just lately, I noticed a hole in the drivers side downtubes, just above the collector, caused by the lower clutch push rod's interference. I will have to pull the LH hedder, ding in the interference area and have a buddy weld on a patch. Yeah, yeah, I know "Rams Horns would never do that, Bla Bla Bla."
The rams horns the PO put on the former SBC were mismatched. One had a bigger casting and holes for the A.I.R. system, the other side was skinnier and pre-Emissions era. No way they flowed equally. Headers was an easier way to go.

On the 292 L6 in my '69 C/10 Stepside, I put Clifford Research long tube headers, a 390 CFM 4 Bbl Holley and an Offy intake. The stock cast iron intake/exhaust system was a lot of inefficient extra weight, and could only work with a single Rochester Monojet. I did that mod in 1978. That 292 ran 250,000 miles until I pulled it in 2002. I rebuilt the OEM 292 [which I'd saved in crates] and had my machinist hot tank and bead blast the Offy and Clifford headers. The Holley was toast after 25 years, so I got an Edelbrock 500 CFM AFB clone. The headers and the intake came out looking new. I repainted the headers with VHT in Cast Iron Grey. The intake is natural aluminum.
That combo is still rocking the ''new'' [2005] 292 in the Stepside now.
[But I do live in Arizona.]
For my money, headers are a lot lighter than the cast iron, give better low-end torque, and just sound b!tchen. But it's a free country.

[BRL]

Originally Posted by '68OrangeSunshine

...For my money, headers are a lot lighter than the cast iron, give better low-end torque, and just sound b!tchen. But it's a free country.

Yep, and that makes me free enough to agree with you.

Had a friend at Walt's replace the Flomasters that dumped just behind the cab with some type of Hemi mufflers that dump behind the rear axle.

Started it for the first time and wondered if the engine was actually running.

I have two stereo amps under both bucket seats, so I put the tools under the hood and lightened up the weight with an aluminum intake too, to compensate somewhat.

...it's so quiet...and of course sounds bicthen!

...you ought to hear the stereo!



Be sure the headers are fitted good, sealed right, and then remove and ceramic coat if you want.

I drive with my hood down so personally I don't care.

No regrets !

[Aberdare]

Originally Posted by special-K

Cheap headers suck. Cheap gaskets suck. Cheap women...

well that all sucks and blows big chunks!

[volksworld]

when i put the small block in my truck i went with headers...in the 10 or so years it was in there i think i replaced the exhaust gaskets 10 times...so when the big block went in i went with cast iron manifolds with no regrets....or course the quality of the 100 dollar headers and non reinforced Mr Gasket header gaskets available 40 years ago was crap and the alternator bracket that attached to the 2 front header bolts was even worse....i'm sure there are hi dollar headers available now with flanges thick enough to seal and reinforced gaskets that wont blow out (stuff like gale banks made for motorhomes with 5/8 flanges )but i couldnt afford them then or now.....and btw can you make baked potatoes in that tool box?

[7 Devils]

I typically go with headers, store bought or a set I fabricate depending on application. The deal with headers sealing and lasting is and always will be the build quality of the product.
I have the tools/equipment to build my own or alter others products. That makes a big difference.

Dan

[special-K]

Originally Posted by BCOWANWHEELS

Pros for headers, look cool

cons
they rust out quick
expensive
leak like crazy

You've convinced me that the cheap headers I ran on my Camper truck that sat long periods of time (worst thing for exhaust "tube") from '89-'04 were expensive, rusted out, and leaked like crazy. I guess the same is true for the set on my '72 K2500 that is running the headers and system I put on in '04. I better go replace that junk right away. Thanks for pointing all this out or I never would have known.

I apologize for the smart a reaction, but such absolute blanket statements like posted are pure worthless close minded inaccurate myth that runs contrary to examples posted here that should open up a mind capable of believing in real life examples given. The only headers I ever had rust out are the pair I removed in '84 that laid in the back of a Blazer till a few years ago, with the hatch uncloseable and trans tunnel removed, up on a mountain that sees a lot of socked in misty days. Not to mention it was a greenhouse for poison ivy. Then again, the Hickey gas tank skid plate also rusted in two into a couple pieces of crumbly junk