Wehrli Custom Fabrication WCF100415-RAW Billet Upper Valve Cover Set LLY/LBZ/LMM Duramax

The Wehrli Custom Fabrication WCF100415-RAW Billet Upper Valve Cover Set is designed to upgrade the appearance of LLY, LBZ, and LMM Duramax engines with precision-machined aluminum construction. These CNC-machined billet aluminum covers replace the factory plastic upper valve covers with high-quality components that deliver both form and function.

Key Features:

• CNC machined from billet aluminum for superior strength and appearance
• Includes both left and right upper valve covers
• Integrated o-ring seal replaces OEM gaskets and eliminates the need for silicone sealers
• Flush head stainless steel hardware included for clean installation
• Black anodized #10 JIC (-10AN) fittings installed
• Raw aluminum finish ready for custom polishing or painting
• Built-in clearances accommodate performance engines equipped with rocker studs
• Made in the USA

Important Installation Notes:

• These valve covers do not include OEM-style mounting bosses for factory fuel filter housing brackets
• Modifications to wire harness tabs and mounting brackets are necessary for installation
• Best paired with top outlet billet thermostat housing and upper coolant pipe kits, as these covers do not include brackets for side mount routing of the OEM setup

Optional custom powder coat finishes are available for those seeking a personalized appearance. The raw finish provides maximum flexibility for custom finishing while the precision machining ensures proper fit and function. This is a direct upgrade for 2004.5-2010 GM Silverado and Sierra trucks equipped with 6.6L Duramax LLY, LBZ, or LMM engines.