Help deciding on headers for my 350
 

Can you guys give me suggestion on my header choice or even some food for thought on choosing the right headers?

Stock smogger 350
601 heads
Th350
Stock mild cam

Thanks, Mark

By the way it's a daily driver.

1 1/2 primary pipes,read the instructions to see which headers install easy and have room to change plugs.dont buy the cheapest ones you want them to last

i'm looking at 1 5/8" primary pipes with a 3" collectors.
As far as them lasting i get that also don't want excessive engine compartment heat.
any reason you suggest 1 1/2" primary pipes?

With the stock motor, the 1 1/2 primaries will bump up the off idle and midrange torque better than a bigger header will. Youre trying to improve the flow with-in the engines operating range. This is one of those areas where bigger is not better.
If your engine had a compression bump, better flowing heads, a larger cam, matched intake, then you would want the larger headers.

Hooker makes a great fitting header, they offer different colors of ceramic coating, and they last. I got 25 years out of my last set of Hookers.

Make sure you read the warrenty of any header that you decide to buy, not all ceramic coatings are the same, and some are not guarenteed.

i hear ya but it wont really be considered "stock" once i get the 601 ported heads with 53cc chambers will it?

it was actually a typo on my part i'm thinking full length headers 1-5/8" primary tubes with 2-1/2" or 3" collectors.

the cam i have now is the E-274-S - Elgin Industries : Online Catalog

Product Description
Fits: 1955 to 1994 283ci - 305ci - 307ci - 327ci - 350ci - 400ci

• 258°/269° Adv. Dur.
• 112° Lobe Center
• 40° Overlap

• Idle Quality: Smooth, stock type
• Power Range: 1000 - 3200 RPM
• Good choice for heavy towing
• Recommended spring pressure 95lbs. for valve on seat; 240lbs. for valve open
• Compression: 9.0:1 or less
• Transmission: Stock auto or Manual

pretty sure from the builders mouth i have the "1470-8" pistons - Keith Black/KB Pistons 1470-080 - Silv-O-Lite Cast Pistons - Overview - SummitRacing.com

page 66 , part #1470- http://www.kb-silvolite.com/assets/0...te_catalog.pdf -


thinking a cam with 216/216 or 218/218 with my stock converter.

Sanderson headers are some of the best around,,that's what I use,give them a call and they'll be glad to help you pick a set of headers for your ride!

Headers
 

Here is a set of Hooker headers. Hooker has been making headers forever! Hooker Headers 2451HKR - Hooker Competition Headers - Overview - SummitRacing.com

thanks! - these are painted so from what i've read they create a lot of engine compartment heat.

i do like that they are available for air injection for my smog setup.

Hello,
On the search for headers for my 72 El Camino SS has led me to some things to think about. Leave the factory AIR system in place or remove it?
Summit offers these Hooker Headers 2451HKR - Hooker Competition Headers - Application - SummitRacing.com
Come to find out they have discontinued part#02451HKR that has holes for the air injector tubes.
I spoke with summit racing’s live chat and he told me the only other ones are these Hedman Hedders 68291 - Hedman Street Hedders - Application - SummitRacing.com for my application.
So Im wondering if I should leave the stock AIR pump setup in place and try to find headers that will work or removed it?

i appreciate your help on this one!
Mark

Headers
 

Well it looks like you have two choices either use the hedman headers or do away with the smog equipment. Is this a show car that you want to keep factory correct? If not take all the smog equipment off and buy the Hooker headers. They are made better. Heavier gauge metal tubes and flanges are probably thicker too. If you have a factory numbers matching car that you take to car shows keep it as it is.

its not a numbers matching car. your suggestion makes sense.

was trying to find a post that read something about the way the air pump functions that it actually helps the car to run better because it aids in the burning of excess fuel as well as aiding in keeping things cooler but cant seem to find it now.
i wondered if someone would come along and post advantages to having the system in place since after all it isn't the system itself that weighs on performance but how the cars were tuned at the factory that these system came stock on.

If the tubes for the A.I.R. are "turned down" into the head pipe (away from the valve), a slight gain in scavenging is achieved. It creates a "low pressure" area ("lowER" is probably more accurate) in the exhaust port. I recall a set of Hookers on a '70 or so Camaro done that way.

"Out of the box", Hooker is the best. Period. Buy them "painted" and send them to a REAL coating shop for a thermal barrier. We use Thermal Tech in hopewell, VA. Jet Hot (TX) and Swain (NY) also come to mind. The thermal barrier ios far superior to the ceramic coatings applied by header companies.

Your 601 heads "modified" are ALMOST as effective as a good pair of 441s or 993s. We've learned through necessity, "flow trumps compression". That is, while compression DOES "make" power, flow makes more. A good pair of heads with 2.02s (properly installed) will produce more power than 1.84s with two full points MORE compression, and be much miore pump gas "friendly".

1 5/8" primary, 3" collector is just right for this application. the 1 1/2" tubes would be okay, too, but no "room" for the future. Keep your exhaust 2 1/2 or smaller.

Jim

The Smog System
 

As you know in the 70's GM started the vehicle emissions control. The AIR system was added to pump fresh air into the exhaust system to help burn partially burned fuel before its ejection from the tailpipe. There was significant unburned and partially burned fuel in the exhaust of early 1970s vehicles, and so secondary air injection significantly reduced tailpipe emissions. However, the extra heat of recombustion, particularly with an excessively rich exhaust caused by misfiring or a maladjusted carburetor, tended to damage exhaust valves and could even be seen to cause the exhaust manifold to glow red. The reason for the unburned fuel in the first place was the smog heads GM produced that would not let the engine breath. The timing on the engines were also set at TDC or ATDC. So it makes sense to get rid of this junk, use better heads, headers or free flowing exhaust, better intakes, and adjust timing to burn fuel in the combustion chamber more completely.

makes perfect sense! thanks for that!
Mark