K&N High-flow Intake System: 2009-2010 GM Half-ton Pickup
If you've got a 2009-2010 GM half-ton pickup (with the 4.8-, 5.3-, 6.0-, or 6.2-liter), K&N says its high-flow intake system can increase horsepower by 16.6 at 5342 rpm over stock. How? The original intake assembly is replaced with an all-new design; it draws air through a K&N filter that never has to be replaced; there's a powdercoated heatshield in place of the stock airbox, and a rotomolded polyethylene tube that air must pass through; thanks to its shape and form, more air gets to the engine. Figure you'll spend $500.
Lingenfelter Magnuson TVS1900 Intercooled Supercharger: 2006-2009 TrailBlazer SS
Available for the 2006-2009 TrailBlazer SS 6.0-liter is the Magnuson TVS1900 intercooled supercharger from Lingenfelter. The company says you can expect 130 rear-wheel horsepower. The supercharger is available in a black powdercoat or chrome finish; other features include a maintenance-free synthetic oil lubrication drive system, a water-to-air intercooler inside the intake manifold, a water-to-air supercharger heat exchanger, a supercharger coolant reservoir and circulation pump, and custom ECM programming. The kit is around $5695, $9995 installed.
Lingenfelter Performance Engineering
Lysholm Supercharger: 2005-2010 V-8-equipped GM truck or SUV
For you readers with a 2005-2010 V-8-equipped GM truck or SUV, there's the Lysholm twin-screw positive-displacement compressor supercharger system. Features include a plenum design with increased volume for unrestricted flow to the intake port and an oversized dual pass air/water charge cooler for a lower discharge temp. The bolt-on system's integrated bypass valve and fuel-rail mount positions are provided. You'll probably pay $5500-$6300.