183506 Water Pump For GM Marine Small Block 4.3L 5.0L 5.7L 183583 183599

Product Overview

This water pump is a direct replacement marine raw-water pump designed for GM Small Block V6 and V8 engines used in inboard and sterndrive applications. It delivers reliable coolant circulation to prevent overheating and ensure consistent engine performance on the water. Boaters and marine mechanics trust this pump for its OEM-equivalent fit and durable construction.

Key Features & Performance

• Precision-engineered cast-iron housing resists corrosion in marine environments
• Direct OEM replacement – no modifications needed for installation
• Includes gasket and mounting hardware where applicable for a complete install
• Designed for continuous duty in saltwater or freshwater cooling systems
• Meets or exceeds OEM flow rate specifications for proper engine cooling

Fitment & Compatibility

• GM Small Block 4.3L V6 marine engines
• GM Small Block 5.0L V8 marine engines
• GM Small Block 5.7L V8 marine engines
• Replaces OEM Part Numbers: 18-3506, 18-3583, 18-3599

Common Uses

• Replacement water pump for inboard marine engines
• Repair and maintenance for sterndrive cooling systems
• Restoration of classic GM-powered boats

Technical Specifications

• Part Number(s): 18-3506, 18-3583, 18-3599
• Engine Type: GM Small Block V6/V8 Marine
• Displacement: 4.3L, 5.0L, 5.7L
• Housing Material: Cast Iron
• Application: Marine Raw Water Cooling

Frequently Asked Questions

Q: Is this water pump a direct bolt-on replacement? A: Yes, it is designed as a direct OEM replacement and includes the necessary gasket for installation on compatible GM marine engines.

Q: Does this pump work for both fresh and saltwater? A: Yes, the cast-iron construction is suitable for both fresh and saltwater environments, though regular flushing is recommended after saltwater use.

Product appearance and specifications may vary slightly by batch. Compatibility may vary by serial number. Verify fitment before purchase.