Exhaust Manifold Set GM LS w/2.5in Outlet

The Exhaust Manifold Set GM LS w/2.5in Outlet from HOOKER delivers the exhaust scavenging performance that serious marine engine builders demand when upgrading LS-series powerplants in boats and watercraft. Whether you're installing a contemporary LS engine in a classic hull or optimizing an existing marine platform, this cast iron manifold pair addresses the core challenge: efficiently routing high-temperature exhaust gases away from the engine block while maintaining backpressure control for peak power delivery.

Manufactured from ductile iron and finished in natural (unpainted) cast, this two-piece manifold set is engineered to withstand the thermal cycling and salt-air exposure inherent to saltwater and freshwater boating environments. The 2.5-inch outlet diameter is sized to optimize exhaust velocity without creating unnecessary backpressure, a critical factor in marine applications where engine cooling and durability directly impact your time on the water. HOOKER's casting design promotes smooth gas flow paths that reduce turbulence and heat accumulation in the engine bay—essential when operating in confined marine engine compartments where thermal management affects both performance and longevity.

This manifold set is purpose-built for GM LS-series engines, including LS1, LS2, LS3, and related platforms commonly swapped into marine applications. Weighing 30.55 pounds and measuring 12 x 9.3 x 20.6 inches, the pair fits standard marine mounting locations and pairs cleanly with aftermarket exhaust systems, risers, and through-hull fittings. Installation requires proper header gaskets and stainless steel fasteners rated for marine corrosion resistance; ensure your exhaust line sizing matches the 2.5-inch outlet for maximum scavenging efficiency and compliance with EPA sound regulations in your boating region.