Cometic C9787 HD 1340 Copper Cylinder Base Gasket 3-13/16" Bore .005" Pair

The Cometic C9787 is a precision-engineered copper cylinder base gasket designed specifically for Harley-Davidson 1340 Evolution Big Twin engines with oversized 3-13/16" bore cylinders. This high-performance gasket set includes a pair of gaskets to service both cylinders.

Key Features:

• Premium copper construction for superior sealing and heat dissipation
• .005" compressed thickness allows precise deck height adjustment
• 3-13/16" bore diameter accommodates big bore cylinder applications
• Sold as a matched pair for complete base gasket replacement
• Designed for Harley-Davidson 1340cc Evolution engines
• Made in the USA with quality American materials

Cometic copper base gaskets are ideal for performance engine builds where precise piston-to-head squish area is critical. The thin .005" profile provides minimal compression height adjustment while maintaining excellent sealing properties. Copper gaskets conform well to slightly irregular surfaces and provide consistent sealing under high cylinder pressures and extreme temperatures.