Headers vs. Stock Manifold

[Stingray74CC]

I'm looking for advice. My driver's side exhaust manifold has a crack. Do I replace it with the correct replacement or go for the headers? There is about a $300 price difference between the choices. Considering I go with the Hooker Super Comp. Ceramic Coated Headers, which are the ones I like....or the correct replacement.

I've been told that the factory manifolds are very well designed and headers would not add very much as far as performance is concerned and may even be too hot. What differences would I notice with a good set of headers versus the stock exhaust manifold?

The noise has to go...it's gonna be one or the other.

Thanks for the input.

 

[400hp_76]

Im no scientist but i do know that the stock manifolds are about, what 40 pounds a piece....maybe a little exageration but heck, you could probably pick up a tenth from weight with the super comps. I also know that the headers will give you more horsepower. and no offense but whoever said it want make that much of a difference must not think around 20 to 25 more horses is a lot. I would dare say 15-20 at the wheels. just a gestimation. but hooker knows there stuff.

 

[69MyWay]

Remember headers require some mods usually to put them in, and they don't alwasy fit the first time. I suggest getting them as painted style, bending, denting, grinding, fitting them, then sending them out to be coated.

You also have to factor in the exhaust work to weld the collectors to the rest of the exhaust.

My vote is for headers, but it will be an aweful lot of work for you over the next couple of weeks to go with tubular headers. The engine will love you for it though.

 

[Paranoid]

I'm guessing you're talking about BB Manifolds?? I've read in "How to Hot-Rod the BB Chevy" that the Corvette (C3)exahust manifolds are the lowest restriction stock exhaust manifolds. The difference in HP though can be between 20-50HP using headers depending on your engine tune. You can order one manifold for about $300-$350 maybe cheaper. If your looking for all out performance, go with the headers.

I just ordered the stock exhaust manifolds for my BB for $497/pr. I wanted/needed a setup that would be an absolute bolt-together system and headers just don't fit that thinking. You can increase the flow in these already low restriction manifolds by grinding away the bump in the manifolds.

 

[Nut]

Anthony,

I picked up 35 Dyno tested hp on my lowly SB with headers. Mine fit in without any mods but that BB of yours fills up the engine bay a tad bit more than my 350. That car will never be stock so I say ..... go for it. I can't wait to drive it afterwards.

........... Nut

 

[mmvette80]

Nut, Is that 81 engine stock?

 

[Stingray74CC]

Thanks for the replies

I'm thinking that I'm gonna go with the headers. I do need to find out the cost of ceramic coatings. The super comps with ceramic coatings are about $652 versus $508 for a black finish. Can't wait to get them.

Oh, Nut, you're more than welcome to take her for a spin. She's running much better than the last time you drove.

 

[400hp_76]

I bolted my Super comp full length headers straight up. No modifications. Only thing was rewelding the exhaust back up. Mine were a perfect fit. Maybe luck, i dont know, but i have heard some bad stories about dynomax and other headers. Just what i have heard, super comps are pretty much straight up. IM sure there is the occasional bad bend.

 

[RLP]

I like the stock exhaust manifolds. Headders crack, rust out and are a lot of trouble.

 

[400hp_76]

No offense RLP, but i disagree. what exhaust is gonna look good and not rust after, say 4 years heck even 1 year. Headers if they arent bare metal, and are ceramic coated will last a long time. the right ceramic coating can even make them cooler.

 

[Jack]

Dunno how bad or where the crack is ... but an expert welder with nickel rod may be able to repair it.
JACK:gap

 

[Stingray74CC]

Cast Iron

The manifolds are cast iron right? I talked with a welder. He said that cast iron is very difficult to repair (weld) with any real strength. The previous owner told me that the manifold has already been repaired once or twice. I figured if it has already been toyed with then I'll be better off replacing.

 

[JohnZ]

For a regular street-driven car, headers are a huge PITA whether they're coated or not. Once you get past trying to make them fit and cutting/welding the rest of the system to get them connected, then you get to deal with cracks, exhaust leaks, higher underhood heat, and more heat through the firewall into the car (as if you didn't have enough of that already). Your call, but be prepared to deal with the downside. More power? How often are you at 6000 rpm at wide-open throttle on the street?

 

[Rowdy1]

Matter Of Opinion

Headers have come a LONG way over the years. Do a search on exhaust headers, Jet Hot, Hedman, Doug's, and read up on it. If you do decide to go with them, which I will be doing myself in the VERY near future, get them ceramic coated, INSIDE & OUT. They run a lot cooler than stock, and will not rust. I already know I have to modify mine because nobody make a tuned header to fit Trick Flow angle plug heads. The rest of it should bolt right up. I'll be doing what Chris (69myway) said, buy them plain, do the alterations then have them ceramic coated. The tech's on these sites I listed will reply to your questions within 24 hours and are very knowledgeable & friendly.

http://www.dougsheaders.com/default.cfm
http://www.headersbyed.com/index.htm
http://www.hedman.com/pages/hedmanmain.html
http://www.jet-hot.com/direct.html
http://www.sandersonheaders.com/

 

[Hijinx]

I just got the ceramic coated Hooker Super Comps for my small block '73. I have seen them on a number of C3's and they fit without modification. Very sweet setup. I should have mine installed in a few weeks. Doing a lot more, so its taking me a while.

I lamented over this decision as well. These headers are really very cool. I have seen them after lots of use and with a little care, they stay looking great.

 

[Nut]

Yes Stock L81

mmVette80,

Yes. The engine is bone stock. I have ceramic coated headers into 3" collectors. 3" stainless pipes all the way back to DynaMax muffs. I removed the AIR pump and plugged the hoses. Headers accommodated the O2 sensor. A 2-stage Free Flow cat and a K&N set up and that's it. HP went from 186.3 hp at the rear wheels to 238.4 hp and 336lb-ft torque.

Oh, and the headers have been on the car for over 15 years. Some of the coating is showing some wear but no cracks, rust or leaks. No mods were required and I didn't even have to move and cables or wiring.

........... Nut

 

[78SilvAnniv]

Todays headers...

I have to agree that with technological advances, today's headers are far superior than the old style we knew and hated while growing up.

I had headers on a '74 350 Camaro (1988) and I constantly battled exhaust leaks at the block.

For my 78, I have kept the rams horn exhaust, but I have an older pair on, without the air tubes and connected to ss chambered exhuast and have been VERY pleased with the BB, lope-ing sound. No mods to the engine and I am happy with the slight increase in hp. (of course!)

I recommend you go with the headers. You won't be happy unless you do!
Heidi

 

[Stingray74CC]

You're Right

I'm going with them. I'll be ordering them in a couple weeks. Hopefully to go on the first Saturday that I get them. Ceramic coated of course. I've seen some impressive numbers from stock to header dyno runs. I don't plan on doing a dyno run prior to getting them b/c the engine isn't tip top....got a few other things to take care of first. I will however try to get a sound recording of the before and after. That should be nice too. It sounds good now...hope this doesn't ruin that. I can't see how.

 

[mmvette80]

Nut, sounds good. Thats some increase in hp. Thanks.

 

[Stingray74CC]

Are these a something I should look into?

Dynatech Competition Exhaust System

Browsing the net. Could be something but I don't know.