18-1957-2 Exhaust Manifold Compatible with Mercruiser 340 454 V8 Big Block, Fits Port or Starboard Side, Center Rise Style, Leak-Proof Design, Replaces 89011, MC-1-89011

Restore Peak Performance & Reliability: Premium Marine Exhaust Manifold for Your Big Block V8Is your marine engine suffering from a cracked manifold, water leaks, or rust damage? A compromised exhaust manifold can lead to serious engine issues and safety concerns on the water. Our International 18-1957-2 Exhaust Manifold is the professional-grade, direct-fit solution designed to restore the integrity and performance of your Mercruiser 340 or 454 Big Block V8 engine. Engineered to meet or exceed stringent OEM standards, this manifold delivers superior durability and leak-proof reliability for worry-free boating.Why This Replacement is Critical:The exhaust manifold is a vital component that channels hot exhaust gases safely out of the engine. In a marine environment, it also handles cooling water. A failure here can lead to water ingestion into the engine (hydrolock), causing catastrophic damage. Replacing a worn or leaking manifold with our high-quality unit ensures your engine runs efficiently, stays protected, and provides the power you depend on.Key Features & Benefits:Guaranteed Fit & Extensive Compatibility: This manifold is engineered as a precise replacement for OEM part number 89011 and its vast array of industry equivalents, including Barr MC-1-89011, Sierra 18-1957-2, GLM 51240, and Marine Power 0991-100. It is specifically designed for Mercruiser 340 and 454 cubic inch Big Block V8 marine engines, ensuring a perfect match.Universal, Center-Rise Design for Flexibility: This versatile center-rise style manifold is designed to fit flawlessly on either the port (left) or starboard (right) side of your engine. This unique feature simplifies ordering and installation, as one part serves both sides. It accepts all original mounting brackets and hardware for a true bolt-on replacement.Built for the Marine Environment: Constructed with corrosion-resistant materials and a precision leak-proof design, this manifold is built to withstand the harsh effects of saltwater and freshwater exposure. The rust-proof components ensure long-term structural integrity and reliable performance season after season.OEM Quality for Peace of Mind: We don’t compromise on quality. This manifold is manufactured to meet or exceed the original equipment specifications in both material and performance. You can trust it to deliver the same durability, fit, and function as the factory part, often at a more competitive value.Complete Direct Replacement: Avoid the hassle of sourcing multiple parts. This manifold arrives ready to install as a complete, direct bolt-on assembly. It is designed to seamlessly integrate into your engine’s existing exhaust and cooling system, making the repair process straightforward for professional mechanics and seasoned DIYers alike.

• ✅【Precise Fit for Big Block V8 Marine Engines】This exhaust manifold is compatible with Mercruiser 340 & 454 cubic inch Big Block V8 marine engines. It is a direct replacement for a wide range of part numbers including Mercruiser 89011, Barr MC-1-89011, Sierra 18-1957-2, GLM 51240, and Marine Power 0991-100
• ✅【Comprehensive Compatibility】Beyond core engine fitment, this manifold is confirmed compatible with parts from major marine brands such as Osco 9011, Mallory 9-40506, and various Mercruiser Stern Drive numbers (e.g., 807078A), offering a trusted solution for a broad array of applications
• ✅【Universal Center-Rise Design】Engineered as a versatile center-rise style manifold that fits either the port (left) or starboard (right) side of the engine. This universal design simplifies inventory and ensures correct installation, accepting all original mounting brackets for a seamless fit
• ✅【Leak-Proof & Corrosion-Resistant Construction】Built for reliability on the water, it features a leak-proof design to ensure safety and optimal engine performance. Manufactured with rust-proof components, it delivers long-term durability and withstands the harsh marine environment
• ✅【OEM Quality & Direct Replacement】This manifold meets or exceeds original equipment (OEM) specifications for quality and performance. It is designed as a direct, bolt-on replacement, ensuring a hassle-free installation process that restores your engine to reliable operation