The GM Vortec has what they call a resonator box on the air intake. This black box is hollow inside and serves no real purpose but to dampen the intake noise. The box actually causes turbulance in the air and restricts steady air flow from going directly into the throttle body. Rem,oval of this box is quite simple. After removing the box a 2" hole is exposed that can easily be pluged with a expandable pipe plug you can get at the hardware store. I have noticed a definate increase in horsepower after removing the box.And when driving at higher RPM noticed a slightly louder, throaty type sound. I am impressed with the throttle responce as well after this modification. If you have a Vortec engine you may want to try this mod. :hi:
