GMC 3500 HD Performance Air Intake – Wehrli High Flow Intake Horn, Flat Black (2017–2025). This true 4 in. cast-aluminum turbo inlet replaces the restrictive OEM mouthpiece to increase airflow and sharpen throttle response on L5P Duramax trucks.

Engineered by Wehrli Custom Fabrication, the horn uses a smooth transition and anti-surge face that keys into the compressor cover for optimized drivability. CNC-machined cast aluminum with an O-ring seal and billet #10 ORB PCV barb delivers durability and a precise fit. It is a bolt-on upgrade for stock trucks—no tuning required—and works with OEM and aftermarket cold air intake systems as well as OEM-style drop-in turbochargers. Made in the USA and compatible with L5P 2500/3500 HD and the L5D 2019–2024 Medium Duty platform; replaces GM 12678756, 19432816, and 12682569.

Features

• True 4 in. inlet; 25% greater flow area at compressor inlet
• Flows up to 27% better than stock
• O-ring seal at turbo face; includes mounting hardware
• #10 ORB billet aluminum PCV connection
• Works with stock, OEM, and aftermarket cold air kits
• Supersedes WCFab WCF100721 and WCF100833
• Durable flat black powder coat finish

Questions or planning an install? Call our Austin, TX shop at 512-982-9393 or our Los Angeles, CA area shop at 562-981-6800. We offer professional installation and customization at both locations.

Considering multiple items? Contact us for potential shipping discounts.

We install on premises at both locations.

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