LS1 Exh/Int Guide .3138 OD .502 .2.000 OAL

The LS1 Exh/Int Guide .3138 OD .502 .2.000 OAL from FERREA is a precision engine valve guide engineered for high-performance and heavy-duty applications. This component is essential for rebuilds, performance upgrades, and factory restorations where valve seat integrity and longevity are non-negotiable. Valve guides control valve stem clearance and guide the valve head into the combustion chamber—critical for engine reliability, efficiency, and sustained power output under extreme operating conditions.

FERREA's LS1 guide features a .3138-inch outside diameter and .502-inch bore specification, with a 2.000-inch overall length—dimensions that match OEM LS-series engine architecture precisely. The guide is manufactured to tight tolerances to minimize valve stem wobble, reduce friction, and prevent hot gas blowby past the valve seat. This design maintains proper valve sealing under sustained high RPM and elevated cylinder pressures, protecting valve seats and ensuring consistent combustion across engine cycles. The compact 0.075-pound weight reflects the precision-cast or sintered construction typical of modern performance valve guides.

This guide is ideal for LS-series engine enthusiasts, professional engine builders, and machine shops performing complete top-end overhauls or performance modifications. Installation requires proper reaming and honing to ensure accurate fit within the cylinder head bore; precision fitment is critical to valve alignment and engine longevity. Mechanics and builders targeting both OEM-equivalent durability and enhanced performance in LS1 applications—from street engines to competition builds—will benefit from FERREA's proven reputation for dimensional accuracy and material consistency.