When you buy the Mopar CAI it has a square opening right where the HC tube mod goes. Bought it from SteveWhiteMotors. The difference with the HC lower box is that it has a circle that fits perfectly with the HC MoD tube. The Mopar CAI will work just fine. The HC tube was apx $70.00 and the Mopar CAI was apx 300.00 or around that.