Headers -Info request

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by Goldie, Aug 17, 2008.

  1. Goldie

    Goldie Epic Member 5+ Years 1000 Posts

    My vehicle is an 07 Sierra Classic WT with the 4.3L six. I am thinking about installing a set of headers for improved performance and mileage. Can you folks provide me with recommendations as to the brand, results and experiences you have had with headers? I have a cat-back exhaust system on the truck now. Thanks in advance for your help.
  2. mehoff400

    mehoff400 Rockstar 100 Posts

    personaly think you would be better off spending money on an intake first before headers on a new truck
  3. sierraman

    sierraman Rockstar 100 Posts

    i have gibson headers on mine, didnt really help with gas milage all that much, i would also go with the intake before headers because headers and installation can run 6 or 700, not really worth it in my opinion
  4. zippy

    zippy Rockstar 100 Posts

    I've been running headers since the early 70's and always found them to give noticeable extra power. But, my experience is limited to 350's and 454's. I don't know how much extra you'd notice with a 4.3L. With headers, in conjunction with a dyno tune, I've had to re-jet carbs or change EFI control chips to take advantage of the increased breathing. In addition to the change in exhaust flow, headers are different from cast manifolds in several respects:
    • You may notice more noise in the passenger compartment. It's more in smaller cars where you were closer to the old "quieter" manifolds, so the new headers are louder. I mean noise coming thru the firewall and floor, not the exhaust noise. It's not that bad in a full size truck where the exhaust isn't tight.
    • Headers are notorious for leaking. Some of it's a bad rap because of poor installation. The newer ones have thicker flanges that are more stable than the old school ones. Of course, the thicker flanges make them heaver. Something that's not mentioned much (outside of race circles) is the weight savings with headers -- it's significant. Don't cheap out on your header bolts, use premium gaskets and you probably won't have any trouble. The installation instructions will tell you to re-tighten the bolts after a while -- do it.
    • Headers are not diamonds and they're not forever. Like other exhaust pipes, they will eventually burn thru. I highly recommend that you take advantage of the ceramic coatings available these days. The will extend the life of you headers, control heat (see below), and the look much better than burned paint and rust.
    • Headers are hotter than manifolds. It's simple thermodynamics... they're thinner and have a larger surface area than manifolds, so they conduct more heat into the engine compartment. This can significantly warm a poorly vented under hood area. (Another reason for the ceramic coating.) To be considered in a hi-per V8 car but not a problem with a 4.3 full-size truck.
    • Emissions control. In the old days there were stories of header exhausts that would loose so much heat before before the cat, that the it wouldn't get hot enough to perform correctly. These days your main concern is that your headers support all the sensors and fittings as the OE manifolds.
    For your V-6, you'll probably get a set of C.A.R.B. approved shorties. These are 50-state legal and bolt up to your existing head pipes. With this type of header there isn't much selection compared to off road full length headers.
    There's no magic in header manufacture, you're paying for labor and materials. Have a look a several sets of shorties. Compare the welds and bends, it's easy to tell which ones exhibit higher standards. Some of the better shorties have their tubes more equal in length. This requires more tubing and bending, so, naturally, they cost more. Instead of spending tons on fancy polished headers, you might consider some cheaper ones and get a computer chip and air intake for a complete package.

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