The K&N 57-3031-1 is a 57 Series fuel-injected performance kit (FIPK) for the 6.0L V8 in heavy-duty Silverado trucks. It replaces the factory air box and intake tube with a black, roto-molded high-density polyethylene tube, a custom heat shield, and an oversized oiled cotton cone filter. The manufacturer says the tube and shield keep intake air cooler than a metal tube would, which supports the denser charge that the company credits for part of the gain.
Per the manufacturer, the kit's estimated gain is 20.34 HP at 4894 RPM and 21.8 lb-ft of torque. Owners on user forums report mixed results: some feel a clear pull in the mid-range, while others notice mostly added intake noise and little change in fuel economy. A drop-in filter that keeps the restrictive stock tube will not match the airflow of a full system, so this kit is the better choice if you want the complete path upgraded. Searches for 2001-2007 Silverado 2500HD 6.0 cold air intake, K&N FIPK 57-3031-1, and reusable oiled cotton HD intake filter typically lead to this kit.
The manufacturer's product listing covers the 2001-2007 Chevrolet Silverado HD and GMC Sierra HD with the 6.0L V8. Some other listings show narrower year ranges, so confirm your truck's year and engine before ordering.
The manufacturer states the washable oiled cotton filter only needs cleaning about every 100,000 miles under normal highway driving. Harsher conditions such as dusty roads or towing will shorten that interval.
Owners on user forums report that filter oil can migrate onto the mass airflow sensor and cause rough running. Their fix is to clean the sensor with an appropriate cleaner and avoid over-oiling the filter when re-oiling it.
The manufacturer says the full system typically installs in under 60 minutes with simple hand tools, and it publishes an installation instruction sheet for this kit. Plan to remove the stock air box, fit the heat shield to the factory mounting tray, and reconnect the mass airflow sensor to the new tube. Take care when handling the sensor and the filter, since oil on the sensor is the most common complaint from owners. Work on a cool engine, follow the instruction sheet's sequence, and tighten the clamps and mounting hardware fully before starting the truck.
