Manifold or headers?

[1987_3/4ton_chevy]

I am currently have my Engine rebuilt. I am getting a few steps higher cam in it as well. I can't decide if i want headers to make it even louder or manifold with exhust? I am wondering what you guys would do? Its gonna be loud with the rebuild being done, with headers would that be over kill?

[exmonkeypunk]

There's no such thing as overkill..... Well, not in my eyes anyways.
Headers will help make more power. You could always use some mufflers that quiet things down a little. It would make it have more of a deep rumble instead of a raped nascar tone. Do you have a stock setup you could bolt on and try first? Or maybe an older aftermarket dual? Either way, headers are always a nice add on for extra everything.

[1987_3/4ton_chevy]

the only thing with Headers is the engine molt is in the way of the 1st hole (not sure the name). I know there is differen't styles headers... which one would be correct? I am totally new on this stuff thats why i am asking these questions

[1987_3/4ton_chevy]

http://www.jegs.com

Item Number 520-2461-1

I belive this will work... maybe?

[GKsport67]

Im at this same stage in my build & i personally am convinced of the header/flowmaster 40 series mufflers. Y? ...because it seems to be the staple in performance/looks/upgrade,if not for you for the guy that may BUY$$$!

I'm not they guy that likes or wants to be loud but I'm SOLD! Go to www.youtube.com n listen to a few setups,stock and non stock!

[Blue_71]

i do have to say my 69 with headers and 40 series has a sound all its own, but after running headers on my 89 for 2 years ill never go to the effort and aggrevation of using them again... never had a single gasket problem (expensive headers) but i had no low end at all and LOST mpg out of it. i went from manifolds with a single 2" exhaust and a turbo muffler, to hedman headers with 2 1/4" true duals, and summit turbo mufflers. its now back to manifolds, 2 1/4" in, dual 2 1/4" out and has the factory power back to it.

my 71 K20 is running Ram Horns, 2 1/4" single pipe to thrush glasspack.. stock 98 350 bottem end, LT1 roller cam, 89 truck TBI heads ported and polised, stock TBI intake ported and polished

71 C10 is running a 327 bored .030, 427/457 lift crane cam, stock 487 heads, ram horns, and 2 1/4" true duals to 98 cadilac deville mufflers (long story )

[BP68]

I think headers. Here is another option if you want to split the difference. A cast manifold that flows better than stock, but looks more vintage and may seal better than headers.

They are made by Sanderson.

[Jtrux]

Just my .02 cents. I love headers. They add power and since you have an aftermarket cam they will allow you to really take advantage of it and another reason I like them, espesially the coated ones is because a good set of headers just looks good.

[70cst]

Originally Posted by Blue_71

i had no low end at all and LOST mpg out of it. i went from manifolds with a single 2" exhaust and a turbo muffler, to hedman headers with 2 1/4" true duals, and summit turbo mufflers. its now back to manifolds, 2 1/4" in, dual 2 1/4" out and has the factory power back to it.

This statement interest me. My 402BB has been rebuilt and beefed up a little and I have been trying to decide whether to go with my my stock manifolds or go with some type of headers. My main concern with headers is that they drop below the frame which I do not want.

[Blue_71]

honestly i have no explaination as to why the truck is that way... back in highschool i wanted to hear it with a straight pipe, so i took the muffler off (this was with manifolds)... sucker would NOT take off on a hill unless it was in low (SM465, 3.73 gears)
something to do with taking backpressure off that engine kills it.. same thing with my K20, with open pipes the thing has no low end. it could be something to do with TBI engines??

the 89 went from 15 mpg with manifolds and single pipe, to 10 mpg with headers, back to 13 mpg with manifolds and single in/dual out. i ran the headers for 35,000 miles... put them on at 210,000 miles and took them off around 245,000

[Pont406]

I always run headers but I also have to add a couple jet sizes or it will be down on power.

[tim21391]

is this gonna be on a dailey driver or everynow and then drive it truck...on my 72 i have stock manifolds going into 40 series flows..and it sounds decent..its not annoying loud...it has a nice rumble but when u punch it..it screams get out of my way... it also makes the neighbors mad too...my truck 402 big block....go to you tube... "1972 Chevrolet C-10 Flowmaster 40 Series".. i have two videos...

[Steelawork'n]

Experimental thought guys. If we open up our exhaust that allows for the potential of more air flow. But if we don't adust the carb to compensate for this potential we might have gas mileage issues. When you add headers and bigger pipes do you also adjust the fuel to air ratio at your intake i.e your carb???

[basketcase]

I used '81 Corvette stainless stockers on mine. They fit like stock and don't leak. You can use the earlier front pipes like '67 327 or make some up. They are cheap at swap meets and give the header look without the hassles. I'm sure that they flow better too but Chevy most likely went to them for weight savings.

Here they are straight from a friends junk pile.



This is during clean up with the AIR tubes cut off.



And here they are with the holes welded up and coated with Eastwood Stainless Header Coating.



Tom

[special-K]

Those Vette manifolds are headers,right?Not only do you adjust the carb when exhaust is changed,you should also re-jet.I don`t notice anything louder with headers or a built motor.That`s all in the muffler and pipe diameter.You can built a hot motor with headers and have it quiet if you want.If you run tri-ys you can help any loss of bottom end.The shorter the header the less benifit.I still like the "one pipe per hole" design,like those Vette manifolds.

[dznucks]

can anyone tell me where to get some of those '81 vette manifolds or provide some more info so i can try and track a pair down?

[basketcase]

Mine are '81s (first year) with a 2" outlet. '82s have a 2.5" outlets and they were used on all Vettes in similar style until the LS1 came out in 1997. There may be some spacing differences if you find LT1 manifolds.

Check Ebay, Corvette swap meets like Bloomington Gold and Corvettes at Carlisle or Corvette sites like www.corvetteactioncenter.com for classifieds. There are also Corvette parts guys at most local swap meets, especially the bigger ones. I paid $35. for mine so don't pay too much just because they are a Corvette part. There really isn't much demand for them.

Try also Corvette salvage dealers like http://www.corvettesalvage.com/ and
http://www.tracyvette.com/ or http://www.jdcorvette.com/

There are lots of used Corvette parts places if you look on the net. I'd bet that you can find some at a local swap meet though. If someone has other Vette parts I'd ask them. They may not think these manifolds are worth dragging around to the meets.

Tom

[chevy72blu]

I vote manifolds on a daily driver... They'll seal up the first time and wont give you problems.

Headers will make more top end HP, but likely loose a little TQ down low due to the lessened back pressure. I cant believe no one covered this in this thread yet. Opening up your exhaust is a good thing to a point, but then it becomes a problem. Engines need a certain amount of back pressure in order to work most efficiently. Now, you can tune your carb to run well with open headers, but just ripping the pipes off a stock vehicle will result in a dog. Too much BP, and you loose power. Too little BP, and you loose power. The key is in tuning and selecting an exhaust setup that works with your combo.

A kid I used to race with out at the strip was alway coming up with half baked ideas to make his car faster.. usually they didnt work and often times they made it slower. One of the first things he did was run a strait downpipe off of his manifold on his 90's something accord. It sounded about as bad as it ran.

When I first started racing, I pulled off my 2" dual pipes and 40 series mufflers and ran strait headers. I picked up a bit on the long end, but it felt sloppy down low- I was a tenth or 2 quicker. I thought that back pressure was just a set thing. When I started researching it and went back to test n tune with a jet kit, I picked up another 1 or 2 tenths.


Back to the OP's question, headers wont necessarily make your exhaust louder. Its just a different sound thats hard to describe; more echoey and tinny sounding which sounds great a cam that has some lope to it.

If anyone that knows more than I do about this, feel free to correct me. I can only comment on my experiences.

[Steelawork'n]

Originally Posted by special-K

Those Vette manifolds are headers,right?Not only do you adjust the carb when exhaust is changed,you should also re-jet.I don`t notice anything louder with headers or a built motor.That`s all in the muffler and pipe diameter.You can built a hot motor with headers and have it quiet if you want.If you run tri-ys you can help any loss of bottom end.The shorter the header the less benifit.I still like the "one pipe per hole" design,like those Vette manifolds.

Thanks for the explaination. It just makes since to to the carb to the exhaust so that as much air can pass through as the engine wants.

[steelhorse]

Go with a tri y header,they will maintain torque and help up top.I have always gained power and mpg.Keep the diameter to 2 1/4 and it will also keep torque also use an x pipe setup

[tim21391]

the only thing i dont like about headers is...they loosen...i was thinking about putting headers and 40 series flows on..and everybody i talked to said no dont do that u will never get a good seal it will leak leak leak so i stayed with manifolds and flows

[Premium72]

it wont get any louder. even with your cam or headers or what not. it will sound different ie better. itll sound a bit thumpy and throughty and ballsy, but itll only be louder if you dont put mufflers on it or put somethn goody like one chambers on it. itll give you some more power and a nice "hotrod" sound...
now just look at what you can afford.
good luck.