HSP Diesel 2004.5-2005 LLY Duramax Max Flow Bridge and Cold Side - 204-HSP

HSP Max Flow Bridge and Cold Side for 2004.5-2005 Chevrolet / GMC Duramax LLY

The 204-HSP, also known as the HSP Max Flow Bridge and Cold Side Tube, is built for the 2004.5-2005 LLY Duramax-equipped Chevrolet and GMC trucks. This upgrade improves airflow, enhances performance, and cleans up your engine bay with a bold, functional design.

Why Choose the HSP Max Flow Bridge and Cold Side Tube?

The factory bridge and cold side pipe on the LLY are known weak points. They are restrictive and poorly designed for airflow, with inefficient bends that limit performance. The factory bridge, in particular, is a major source of power loss and boost leaks.

What Makes the HSP Max Flow Bridge and Cold Side Tube Different?

Both the bridge and cold side tube are upgraded to a 3" diameter, providing a significant improvement in airflow. The Max Flow Bridge is precision-cast aluminum, CNC machined for optimal internal flow and strength. Its pressure-tested to over 100 PSI and secured using two M8 studs, 12-point nuts, and a high-strength O-ring to eliminate the risk of boost leaks.

The Cold Side Tube also features a 3" mandrel-bent design, creating sweeping bends that reduce turbulence and increase efficiency. This setup pairs best with factory or drop-in replacement turbochargers, as it maintains OEM-style intercooler routing.

Whats Included

• 1x Bridge Neck (HSP-IN-209)
• 1x Bridge (HSP-IN-222)
• 1x Coldside Tube (HSP-IN-213)
• 1x Bridge Neck O-Ring (RFB-670-RFAB)
• 1x 1/8'' NPT Brass Plug (RFB-811-RFAB)
• 2x Bridge Neck Stud (RFB-902-RFAB)
• 2x Bridge Neck 12-Point Nut (RFB-903-RFAB)
• 24x 5/8" Heater Hose (RFB-401-RFAB)
• 2x 5/8" Worm Gear Clamp (RFB-403-RFAB)
• 2x 3" T-Bolt Clamp (RFB-422-RFAB)
• 1x 3"x4" Straight Boot (RFB-430-RFAB)

Fitment

• LLY: 2004.5-2005 (VIN Code 2)

How to identify VIN Code: The 8th character of the VIN indicates the engine code. The 10th character indicates the model year.

Overview

• Increased performance and turbo spool-up
• Powder coat options to enhance engine bay aesthetics
• High-strength silicone boots
• Enhanced engine sound
• 3" Mandrel-bent cold side tube
• 3" Precision-cast aluminum CNC-machined bridge

Our Warranty

HSP NO BS LIMITED LIFETIME WARRANTY

At HSP, we believe in the quality of our products and stand firmly behind every part that leaves our facility. For years, we've gone above and beyond for our customers—and now we're formalizing that commitment. Our No BS Warranty outlines the process and expectations clearly, so you can shop with confidence.

Click here to read our full Lifetime No BS Warranty