Wehrli's WCFab 4" high-flow cast intake horn for 2001–2004 Chevrolet Silverado and GMC 2500/3500 HD trucks with the LB7 6.6L Duramax replaces the OEM turbo mouthpiece to improve airflow and spool. It flows about 40% better than stock, works with stock or drop-in IHI turbos, and fits systems using a 4" boot connection. Includes mounting hardware and a custom powder coat finish; made in USA.
Wehrli 01-04 Duramax LB7 4in High Flow Intake Horn - Bengal Blue