cold air intake

[aintnoV8]

been doing some research on these systems. seems kind of pricey, even though once you buy one im sure it will pay off eventually. i considered building my own cheaply. the only thing im wondering is what size universal filter would be good for my truck. i have a 2004 chevy 1500 4.3, i was going to get a cone filter by Airaid - # 6'' Base, 4-5/8'' Top, 9'' Height, 3'' Flange. seems big enough for the amount of air needed to pass through. probably will build a bounding box to exclude it from the heat off the motor. for piping it would be basic 3" exhaust pipe connected with pvc flexible coupling and adapted to the throttle body. came out to roughly $100. any input? size filter suggestion? what you would do different?