Sierra 18-1957-4P Exhaust Manifold Kit MerCruiser 7.4L/8.2L Big Block

• Mercruiser exhaust manifold
• Direct replacement manifold fits Mercruiser GM V8 454 and 502 cu. in. engines with center riser
• For Mercruiser 330; 340; & 454 Magnum model engines
• Interchangeable between port and starboard side
• Heavy duty cast iron
• Painted black
• Includes all gaskets; short riser studs; drain elbow; and plugs
• Replaces Mercruiser 89011A8; 807078A2; 807078A4; 807078A6; 807078T09; 807078T10
• Replaces Mallory 9-40506
• Replaces Osco 9011A
• Replaces Sierra 18-1957; 18-1957-1

• Sierra 4 inch exhaust elbow
• Fits most Mercruiser V6 & V8 applications
• Accepts 4 in. inside diameter exhaust hose
• Cast iron construction
• Includes 18-0897 gasket; 18-4263 pipe plug; and 18-4258 pipe plug
• Replaces Mercury 44354A3; 807914A1; 807988A2 and 807988A03
• Replaces Osco 4354
• Replaces Sierra 18-1976 and 18-1976-1

Complete exhaust manifold and riser set for Mercruiser big block GM V8 engines. Kit Includes: 2 Cast Iron Center Rise Exhaust Manifolds 2 4" Exhaust Elbows 2 manifold gaskets and 2 riser gaskets Exhaust Kit For Mercruiser Big Block V8 454 CID Center Riser with 4" exhaust. Package includes:2-18-1957 Manifolds 2-18-1976 Risers. NOTE: Gaskets Included.