Exhaust Manifold Set GM LS Rear Dump

The Exhaust Manifold Set GM LS Rear Dump from HOOKER delivers the performance and reliability that serious boaters and marine engine builders depend on when upgrading LS-series powerplants. Whether you're installing a modern LS engine in a classic boat, optimizing airflow on a high-output ski tower installation, or rebuilding a damaged exhaust system, this cast-iron manifold pair handles the heat and pressure of marine duty while maintaining clean exhaust routing. Designed specifically for rear-dump applications, this manifold set eliminates restrictive OEM components and allows engineers to customize exhaust exit points for improved cooling and aesthetic control.

Constructed from heavy-duty cast iron with a natural finish, the HOOKER 8505HKR manifolds feature a 2.5-inch outlet diameter that balances scavenging efficiency with manageable backpressure across the full operating range—critical for marine engines that must perform at both idle and wide-open throttle. The rear-dump configuration prevents exhaust gases from flowing through underbody passages, reducing underdeck heat buildup that can damage wiring, fuel lines, and structural components in tight engine compartments. The pair weighs 25.65 pounds total, accounting for the robust wall thickness required to withstand thermal cycling and saltwater spray exposure common in marine environments.

This exhaust manifold set fits all GM LS-series engines and suits both freshwater and saltwater applications when paired with appropriate corrosion-resistant piping and through-hull fittings. Installers should verify clearance with surrounding components—engine bay layout varies widely between boat models—and ensure proper sealing with quality gaskets rated for marine exhaust temperatures. The manifolds arrive ready for bolt-on installation; port sizing and outlet positioning make them ideal for custom wet-joint systems, poppet valve installations, or direct transom exhaust exits on performance and restoration builds.