3 1/2" Turbo Intake Horn for the 2017-2019 L5P Duramax with factory style Turbo. The OEM plastic intake horn is 2.4" diameter and we experienced a 25HP Gain (Dyno comparison above) with our 3.5" Horn when used with a Max Effort Tune. Tuning recommended with this part. Kit Includes PCV Hose and fitting to reroute the PCV.
See WCF100721 Horn with PCV Port as a bolt on alternative for stock trucks with no tuning required.