Intake Gasket - Buick 400-455

The Intake Gasket for Buick 400-455 big block engines is a critical OEM-specification replacement component designed for mechanics and restoration enthusiasts rebuilding or servicing classic Buick performance motors. This pair of gaskets seals the intake manifold to the cylinder head, preventing vacuum leaks and coolant seepage that compromise engine efficiency, drivability, and longevity. Whether you're tackling a complete engine overhaul, diagnosing rough idle conditions, or refreshing a tired big block, a quality intake gasket replacement is non-negotiable for reliable operation.

This intake gasket pair features composite construction with a 0.032-inch thickness engineered to withstand the thermal cycling and pressure demands of big block Buick combustion. The 1.15 x 2.38-inch rectangular port configuration matches the intake manifold and head port geometry precisely, ensuring uniform clamping load distribution and eliminating hot spots that lead to gasket failure. Composite material provides superior conformability compared to cork or steel alternatives, accommodating minor surface irregularities while maintaining a consistent seal across the full operating temperature range of street and performance applications.

Mechanics restoring 1970–1976 Buick 400 and 455 cubic-inch engines will find this gasket pair essential for any manifold removal or head gasket job. Proper installation requires a clean, flat sealing surface on both the cylinder head and intake manifold, torqued fasteners in a crisscross pattern, and verification of vacuum integrity post-assembly. This pair supports both stock intake manifolds and performance aluminum units, making it a universal solution for big block Buick engine builders focused on eliminating vacuum leaks and achieving smooth idle quality.