Intake Manifold Gasket – Fits MerCruiser 3.7L I/L4 (Replaces 27-70905)
Intake Manifold Gasket – Fits MerCruiser 3.7L I/L4 (Replaces 27-70905) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Intake Manifold Gasket – Fits MerCruiser 3.7L I/L4 (Replaces 27-70905)
Product Details
This Intake Manifold Gasket – Fits MerCruiser 3.7L I/L4 (Replaces 27-70905) is designed for a precise fit on Mercury/MerCruiser 3.7L inline 4-cylinder engines, from 165 to 190 HP, manufactured between 1976 and 1989. It creates a reliable seal between the intake manifold and the cylinder head, preventing vacuum leaks and ensuring optimal engine performance.
It serves as a direct replacement for Mercury/MerCruiser 27-70905, Sierra 18-0158, Barr MC472770905, and GLM 31750.
- Engineered for direct-fit, surface-mount installation.
- Manufactured to meet or exceed OEM specification compliance for reliability.
- Designed for use with gasoline fuel systems.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury/MerCruiser | 27-70905 |
| Sierra | 18-0158 |
| Barr | MC472770905 |
| GLM | 31750 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For MerCruiser models, always verify compatibility using your engine's serial number against the ranges provided in the 'Notes' column.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | 165 (2 BBL.) | 165 HP | 4-Stroke | 1987 | 27-70905 | Serial Range: 0B434941-0B774251 |
| MerCruiser | 170 (2 BBL.) | 170 HP | 4-Stroke | 1985–1986 | 27-70905 | Serial Range: 6916779-0B434940 |
| MerCruiser | 180 (4 BBL.) | 180 HP | 4-Stroke | 1987 | 27-70905 | Serial Range: 0B436391-0B775248 |
| MerCruiser | 190 (4 BBL.) | 190 HP | 4-Stroke | 1985–1986 | 27-70905 | Serial Range: 6916779-0B436390 |
| MerCruiser | 3.7L (2 BBL.) | 165 HP | 4-Stroke | 1988–1989 | 27-70905 | Serial Range: 0B774252 & Up |
| MerCruiser | 3.7LX (4 BBL.) | 190 HP | 4-Stroke | 1988–1989 | 27-70905 | Serial Range: 0B775249-0C762299 |
| MerCruiser | 470 (2 BBL.) | 170 HP | 4-Stroke | 1976–1984 | 27-70905 | Serial Range: 4208730-6916778 |
| MerCruiser | 485 (2 BBL.) | 185 HP | 4-Stroke | 1980–1982 | 27-70905 | Serial Range: 5685394-6218036 |
| MerCruiser | 488 (4 BBL.) | 185 HP | 4-Stroke | 1983–1984 | 27-70905 | Serial Range: 6170297-6916778 |
| MerCruiser | 470 MIE | 170 HP | 4-Stroke | 1980–1981 | 27-70905 | Serial Range: 5520115-6218036 |
Technical Specs
- Product Type
- Intake Manifold Gasket
- Installation
- Direct fit, surface mount
- Fuel Type
- Gasoline
- Dimensions
- 22.0 x 7.0 x 1.25 inches (558.8 x 177.8 x 31.75 mm)
- Weight
- 0.19 pounds (0.086 kg)
- Other Technical Attributes
- OEM specification compliance
What’s in the Box
- 1 x Intake Manifold Gasket (27-70905)
Installation Notes
- Disconnect the battery and drain the engine coolant into a suitable container.
- Disconnect all fuel lines, vacuum hoses, and electrical sensors attached to the intake manifold. Label them for easier reassembly.
- Carefully unbolt and remove the intake manifold from the cylinder head.
- Remove the old gasket and thoroughly clean both mating surfaces of any old gasket material, sealant, or debris.
- Position the new gasket correctly, ensuring all bolt holes and ports align perfectly.
- Reinstall the intake manifold and tighten the bolts in the manufacturer-specified sequence and to the correct torque values.
- Reconnect all hoses, lines, and sensors.
- Refill the cooling system, start the engine, and carefully check for any coolant or vacuum leaks around the gasket area.
Troubleshooting & FAQ
How do I know if my intake manifold gasket is failing?
Common signs of a bad intake manifold gasket include engine overheating, coolant leaks (often visible near the top of the engine), a rough idle, poor engine performance, or a "check engine" light related to vacuum leaks or misfires.
Is this gasket compatible with all MerCruiser 3.7L engines?
This gasket fits a specific range of 3.7L models from 1976-1989. It is critical to check your engine's serial number against the compatible ranges listed in our Engine & Model Compatibility table to ensure a perfect fit.
Do I need to use sealant with this gasket?
Generally, modern gaskets like this one are designed to be installed dry. However, always consult your engine's service manual for specific procedures. Some applications may require a small amount of sealant at corners or coolant passage junctions.
What is the recommended replacement interval for this gasket?
There is no fixed replacement interval. Gaskets are typically replaced only when they fail or during other major engine service, such as a top-end rebuild. Regular inspection for leaks is recommended.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost?
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns?
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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