860373 860373A4 8M0061387 Mercruiser Intake Manifold | Genuine Used Part

🔧 Product Description

Genuine MerCruiser 5.0L / 5.7L Vortec Four-Barrel Intake Manifold - Part Numbers: 860373 / 860373A4 / 8M0061387

A genuine used cast-iron four-barrel intake manifold for GM-based MerCruiser 5.0L and 5.7L V8 Vortec marine engines.

The manifold uses the eight-bolt Vortec cylinder-head pattern and supports a four-barrel carburettor or compatible throttle-body system. Mercury service assembly 860373A4 has been superseded by 8M0061387.

⚙️ Key Features

• Genuine Mercury MerCruiser Vortec intake manifold
• Original references 860373 and 860373A4
• Current replacement number 8M0061387
• Four-barrel, eight-bolt cast-iron configuration
• Used on 5.0L and 5.7L GM marine V8 engines

🚤 Compatibility

Commonly used on

• MerCruiser 5.0L four-barrel Vortec engines
• MerCruiser 5.7L / 350 CID four-barrel engines
• Volvo Penta GM-based 5.0L and 5.7L marine engines
• Indmar, OMC and Marine Power Vortec applications

Typically suits

• Engine models:
• MerCruiser 5.0L V8 four-barrel
• MerCruiser 5.7L / 350 MAG carburetted applications
• Volvo Penta 5.0L and 5.7L engines using 3856270
• GM Marine 305 and 350 Vortec V8 engines
• Other marine engines using the same eight-bolt four-barrel configuration
• Engine Size: 5.0L / 305 CID and 5.7L / 350 CID
• Induction Type: Four-barrel carburettor or compatible marine throttle system
• Year Range: Approximately 1997 - 2015
• Fitment Requirement: Verify eight-bolt pattern, carburettor pad and water passages

🔌 Function

The manifold distributes the fuel-air charge to all eight cylinders and routes coolant through the engine's upper water passages.

⚠️ Common Signs of Failure

• Vacuum leak or lean running
• Internal coolant leakage
• Corrosion around the thermostat or water crossover
• Cracked casting
• Warped intake or carburettor mounting surfaces

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 8M0061387 → Supersedes 860373A4
• 860373A4 service assembly
• 860373 casting or shortened reference

OEM / Related Numbers

• 8M0061387
• 860373A4
• 860373
• Volvo Penta: 3856270
• GM 5.0L / 5.7L four-barrel Vortec marine manifold
• Eight-bolt intake pattern
• 860373A4 was supplied with an intake-gasket set and pipe plugs

Aftermarket / Verified Equivalents

• Alloyworks four-barrel Vortec marine intake manifold for 8M0061387
• Marine Engines 4 Less cast-iron replacement for 8M0061387 / 3856270
• Generic 5.0L / 5.7L four-barrel eight-bolt marine Vortec manifold
• Aftermarket fitment commonly covers MerCruiser, Volvo Penta, Indmar, OMC and Marine Power
• Confirm carburettor pattern, coolant passages and accessory bosses

📦 Condition

• Genuine used part
• Removed from running engine where applicable
• In good working condition unless otherwise stated