2004-2005 Engine Coolant Return Pipe 2004.5-05 LLY 304SS Polished (119001130) 2014-2019 EcoDiesel tonneau covers Drilling may be required for

Drilling may be required for installation on some models

0L Duramax diesel models with single exit exhaust

4% larger flow area than OEM

1/8" Laser cut washer

dual add-a-leaf kit #113209 for tail high

2004-2005 Engine Coolant Return Pipe 2004.5-05 LLY 304SS Polished (119001130) 2014-2019 EcoDiesel tonneau covers Drilling may be required forDescription Specifically designed for use in conjunction with the factory thermostat housing. 304 stainless steel construction prevents corrosion compared with OEM mild steel pipe which is prone to rusting and eventually leaking. Allows for installation of factory turbo coolant return thermostat. Also great for marine applications.