Intake Port Seals (8pk) LSXr/LSXrt/LS1/LS6/LS7

The Intake Port Seals (8pk) for LSXr, LSXrt, LS1, LS6, and LS7 engines are precision rubber gaskets engineered for F.A.S.T. intake manifold applications. Each pack contains eight seals sized to 1.344 x 3.66 inches, matching the rectangular port geometry of these LS-platform architectures. These seals form the critical interface between intake manifold and cylinder head, preventing vacuum leaks that would degrade fuel mixture control and idle stability.

Proper sealing at the intake port is fundamental to LS engine performance tuning. Vacuum leaks downstream of the mass airflow sensor introduce unmeasured air that bypasses the fuel injectors, causing lean conditions, rough idle, and check-engine codes. The rubber composition of these seals provides the necessary compression set to maintain contact pressure across thermal cycles—critical when ambient and combustion temperatures swing 200+ degrees Fahrenheit. The eight-pack format supplies a complete OEM gasket set for full manifold installation, eliminating the need to source seals individually.

LS engine builders and tuners replace intake port seals during manifold upgrade, head gasket service, or whenever boost or nitrous fuel system modifications demand fresh sealing surfaces. Whether assembling a stock replacement or a modified engine destined for track duty, these F.A.S.T.-specific seals ensure that fuel trim and idle quality depend on calibration choices, not on air leaks. Compatibility spans naturally aspirated LSXrt and forced-induction LSXr platforms alike.