2017–2023 GM 6.6L Duramax L5P HP4 to DCR Fuel Pump Conversion Kit - Industrial Injection - 608990

When you’re repairing a failed high-pressure pump or upgrading for long-term confidence, this HP4 to DCR fuel pump conversion kit is built specifically for the 2017-2023 GM 6.6L Duramax L5P. It replaces the factory-installed HP4 high-pressure fuel pump with a DCR fuel pump and includes the fuel tubes required to complete the swap cleanly and correctly.
The result is a purpose-built, OEM-style conversion that supports consistent high-pressure common rail operation for daily driving, towing, and demanding use.
Product Spec Sheet: Click Here
Key features
Converts L5P Duramax from HP4 to DCR high-pressure fuel pump
Includes low-pressure supply/return and high-pressure rail/pump fuel tubes needed for installation
Direct-fit kit engineered for the GM 6.6L L5P fuel system layout
What’s in the box
(1) DCR fuel pump
(1) High-pressure pump fuel tube
(1) High-pressure rail fuel tube
(1) Low-pressure supply fuel tube
(1) Low-pressure return fuel tube
(1) Supply hold-down bolt
Fitment
2017-2023 Chevrolet Silverado 2500HD / 3500HD 6.6L Duramax L5P
2017-2023 GMC Sierra 2500HD / 3500HD 6.6L Duramax L5P
Replaces / interchanges with (common references): 12676904, 12678993, 12701094, 12731367, 2940500701, 294050-0701, 6040608C9, 6040608C91, 608990, ALLAP54850, ALLAP54851, AP54850, AP54851, IP55
FAQ
What does this HP4 to DCR conversion kit do?
This kit replaces the factory-installed HP4 high-pressure pump on 2017-2023 6.6L Duramax L5P applications with a DCR-style high-pressure fuel pump. It also includes the fuel tubes required to complete the conversion.
What vehicles does this kit fit?
Fits 2017-2023 GM 6.6L Duramax L5P applications:
Chevrolet Silverado 2500HD / 3500HD (6.6L L5P)
GMC Sierra 2500HD / 3500HD (6.6L L5P)
What’s included in the kit?
DCR high-pressure fuel pump
Low-pressure supply fuel tube
Low-pressure return fuel tube
High-pressure rail fuel tube
High-pressure pump fuel tube
Supply hold-down bolt
Do I need tuning after installing this kit?
On most stock-style conversions, this is designed as a direct-fit replacement and typically does not require ECM tuning on an otherwise stock truck. If your truck has aftermarket tuning, modified fuel system components, or additional fuel upgrades, confirm requirements with your tuner before installation.
What’s the difference between an HP4 and a CP4?
“CP4” typically refers to the Bosch CP4 pump used on certain other diesel platforms (commonly discussed on LML Duramax and 6.7 Power Stroke), while “HP4” on the L5P Duramax is generally referring to the factory high-pressure pump used on that application. They’re different pump designs and the names are not interchangeable.