860100A1 860100-C Mercruiser Intake Manifold | Genuine Used Part

🔧 Product Description

Genuine MerCruiser 5.0L / 5.7L Vortec Two-Barrel Intake Manifold - Part Number: 860100A1 / Casting: 860100-C

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

The manifold uses the later eight-bolt Vortec head pattern and supports a two-barrel carburettor or the matching marine throttle-body assembly. Casting number 860100-C identifies the core casting used for MerCruiser service assembly 860100A1.

⚙️ Key Features

• Genuine Mercury MerCruiser cast-iron intake manifold
• Service part number 860100A1
• Casting number 860100-C
• Two-barrel Vortec configuration
• Fits GM 5.0L and 5.7L marine V8 engines

🚤 Compatibility

Commonly used on

• MerCruiser 5.0L two-barrel carburetted engines
• MerCruiser 5.7L carburetted ski engines
• MerCruiser Competition Ski and TowSports V8 engines
• GM-based marine engines using the 860100-C casting

Typically suits

• Engine models:
• MerCruiser 5.0L 2BBL GM 305 V8
• MerCruiser 5.7L CARB SKI
• MerCruiser 5.7L Competition Ski Gen+
• Selected 5.7L carburetted sterndrive and inboard applications
• Other GM Marine 5.0L / 5.7L engines using the same two-barrel Vortec layout
• Engine Size: 5.0L / 305 CID and 5.7L / 350 CID V8
• Induction Type: Two-barrel marine carburettor or compatible TBI adapter
• Year Range: Approximately 1997 onward, with confirmed late-1990s and early-2000s applications
• Fitment Requirement: Confirm eight-bolt head pattern, thermostat passages and induction mounting

🔌 Function

The manifold distributes the air-fuel mixture to the eight cylinders and carries coolant through the upper engine.

⚠️ Common Signs of Failure

• Vacuum leaks
• Coolant loss into the intake or lifter valley
• Corroded water passages
• Cracked carburettor pad
• Warped gasket surfaces

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 860100A1 established Mercury MerCruiser intake-manifold assembly reference
• 860100-C casting number
• No confirmed later OEM supersession

OEM / Related Numbers

• 860100A1
• 860100-C
• 860100
• GM 305 CID / 5.0L Vortec marine intake
• GM 350 CID / 5.7L Vortec marine intake
• Eight-bolt Vortec cylinder-head pattern
• 861189A1 related TBI adapter on applicable EFI installations
• 27-series Vortec intake gasket set required

Aftermarket / Verified Equivalents

• Marine Engines 4 Less 5.0L / 5.7L two-barrel Vortec marine manifold
• Michigan Motorz 5.0L / 5.7L two-barrel Vortec cast-iron manifold
• Sealink Marine replacement for 860100A1 / 860100-C
• Remanufactured Mercury Quicksilver 860100A1 assemblies
• Generic eight-bolt cast-iron marine Vortec manifold, subject to passage and carburettor-pattern verification

📦 Condition

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