The GDP 3.5" Downpipe, engineered for the 2017-2023 Duramax L5P, is built to reduce backpressure, improve turbo spool, and lower exhaust gas temperatures (EGTs). Designed for serious truck owners who need better airflow, stronger pulling power, and improved efficiency, this upgrade is the direct-fit solution for increased durability and performance.
Manufactured from high-quality materials, the 3.5-inch diameter design increases exhaust flow, allowing your engine to run cooler and perform better under heavy loads. Whether you're towing, working, or putting your truck through high-performance conditions, this downpipe delivers the durability and results your L5P needs.
Includes:
✔ Heat Wrap for Thermal Protection – Helps maintain lower under-hood temperatures. ✔ Clamps for Secure Fitment – Keeps heat wrap firmly in place under extreme conditions.
Features:
✔ High-Flow Design – Reduces backpressure for improved turbo response and increased efficiency. ✔ Lower EGTs – Helps keep exhaust gas temperatures in check for engine longevity. ✔ Heavy-Duty Build – Constructed from high-temp materials to withstand extreme conditions. ✔ Direct Bolt-On Fit – Seamless installation for all 2017-2023 Duramax L5P models.
Note: The original part number GDP45001 will transition to 255-01301 in future inventory.
Factory exhaust components restrict performance. The GDP 3.5" Downpipe increases airflow, improves throttle response, and provides better overall efficiency—all in a direct-fit upgrade that keeps your truck running at its best.
