11-16 Duramax LML HSP 3.5" High Flow Mouthpiece Fuel With our unmistakable styling

With our unmistakable styling

Over 8 operating conditions tested

EGT (exhaust gas temp)

and a more efficient/powerful torque curve

11-16 Duramax LML HSP 3.5" High Flow Mouthpiece Fuel With our unmistakable styling2 4 Week Build Time Normally Not designed to work with a factory intake, it will only fit a 4. 5" HSP intake or an aftermarket 4" intake. New HSP Diesel 3. 5" High Flow Turbo Horn Mouthpiece for 11 16 LML Duramax, With this Turbo Mouthpiece you will notice much more Turbo whistle compared to any plastic mouthpiece. Your choice of powder coating. This high flow design deletes the resonator and reroutes the PCV, without the resonator and PCV holes in