For anyone new to the engine hobby, in ascending order from adequate to ultimate,
exhaust plumbing stacks up as follows:
* Stock cast iron manifolds / shorty headers
* Long tube 4 primary into 1 collector (4 into 1) headers (better ones actually tuned to help extract exhaust past stock head bottleneck in desired powerband.)
* Tri-Y long tube headers. 2 sets of 2 primaries paired with each other, and then both pairs combined a third time. (These pull harder, you can feel the difference.)
* Doug Thorley Tri-Y headers. (
This guy was the real deal: Doug Thorley NHRA bio)
* Custom 180° headers chasing ultimate power for $$$$ but also giving you that 'flat crank' sonic signature.
(Think Bundle of Snakes exhaust)
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The best overall perspective is that the factory cylinder heads are the VE (Volumetric Efficiency) bottleneck
on the engines made in the GMT400 era. And furthermore, the exhaust is the bottleneck of the cylinder
heads. And although the most affordable headers are a nice visual engine bay upgrade, they aren't tuned/timed to
use the negative pressure created behind the passage of the previous cylinder's exhaust pulse to help extract the exhaust
from the current cylinder on the exhaust stroke. There's no real perceptible performance improvement, but they
are admittedly easier on the eyes than the cast iron manifolds.
In terms of actual performance improvement that you can feel, the long tube Tri-Y headers are the best you can
implement for the street. Their design leads to an extended torque curve improvement. And of course I've included
the 180° headers just to cover the 'there's always someone faster thanks to their cubic dollars' aspect of this hobby. :0)
This seems to be a popular question, especially for those new to the old truck hobby.
Hope this brief header pecking order explanation helps to sort through all the claims & counterclaims in the land
of exhaust system marketeering.
Enjoy your ride!