Our intake manifold flanges for the L5P Duramax are CNC machined in house from 6061 aluminum and stainless steel Key Features: - They are designed to fit a 3” OD tube and are multi axis machined to ensure proper air flow - This flange set is perfect for anyone with welding skills that wants to build their own custom intake collector/cold side intercooler setup - This flange set is for years 2017 to 2022 - Part # GRD661023 Compatible with: Duramax, Engine & Engine Parts