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1 3/4 primaries VS. 1 7/8 Primaries?

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Old 09-29-2007, 12:14 PM
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Default 1 3/4 primaries VS. 1 7/8 Primaries?

I am looking into purchasing a set of headers and i wanted to know how much would i really lose going to 1 7/8? I have read a couple articles in a magazine stating to go with the 1 7/8...yet this forum seems to swing toward the 1 3/4...why? Supposedly on the dyno i read from the magazines the 7/8's edged out the 3/4's in everything above i wanna say 4k. While under the 4k curve it was comparable. Thank you for any and all input.
Old 09-29-2007, 02:14 PM
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our car does require some backpressure on the exhaust. The Primaries size depends on your displacement or if you have a power booster. 1-3/4 is better for the stock displacement, but if you add a supercharger or stroker, or even throw in a bigger engine like the LSX block the 1-7/8's give you a better power. Some guys even say HP range tells you which headers to get, and 1-7/8's should be saved for 600+ HP.

Not sure what the loss is but I have 1-7/8 on my bolt on car but I plan to drop a stroker in it in the future so I went with the bigger headers now instead of having to pay 1300 bucks twice for the same thing!
Old 09-29-2007, 02:22 PM
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1 7/8 is really only needed when you start pushing big hp numbers or running a high displacement motor or some type of power booster.

1 3/4 will be more than enough for most people on here unless you have plans to go with a larger motor in the future or start pushing over 550hp




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