Mercury MerCruiser Intake Gasket Set | 8M0073380

Mercury MerCruiser Intake Gasket Set | Part 8M0073380

Part Number: 8M0073380
Full Part Reference: 27-8M0073380
Brand: Mercury Marine / Quicksilver
Official Product Type: Gasket Set — Intake
Category: Seals, Gaskets & O-Rings

What It Does

This is the OEM intake gasket set for MerCruiser sterndrive and inboard engines. It provides the complete sealing package required when removing or replacing the intake manifold — covering the mating surfaces between the intake manifold, cylinder heads, and valley/lifter cover where applicable. Using the correct OEM gasket set ensures proper compression, prevents vacuum leaks, and protects against coolant or oil intrusion into the intake tract.

System

Intake / induction system. Interfaces with the cylinder heads, intake manifold, and valley cover on applicable MerCruiser V-block engines. Verify the diagram position for your specific engine assembly before ordering — intake gasket sets can vary by displacement, head casting, and production date.

Kit Contents

Includes the gaskets required to reseal the intake manifold assembly on applicable engines. Specific contents vary by engine application and may include:

• Intake manifold port gaskets (per cylinder bank)
• Valley / lifter cover gasket (where applicable)
• End seals or end rails (where applicable)
• Related O-rings or grommets included in the OEM set

Confirm exact kit contents against the Mercury parts diagram for your engine model and serial number range.

Compatible Applications

Verify fit using your engine model number and serial number against the current Mercury parts diagram. Intake gasket sets are application-specific and can vary by production range.

• MerCruiser sterndrive and inboard V-block engines — confirm by model and serial number
• Use the Mercury parts diagram (part reference 27-8M0073380) to confirm this set is listed for your assembly

For the 8.1L / 496 MAG intake gasket set, see: Quicksilver Intake Manifold & Valley Gasket Set 8.1L 496 MAG | 27-881633T01.

Serial Requirements

Mercury MerCruiser intake gasket sets are production-range specific. Always verify your engine's serial number against the Mercury parts diagram before ordering. Gasket sets for the same displacement can differ between early and late production engines due to head casting or manifold design changes.

Related Parts

Typically replaced or inspected at the same time as the intake gasket set:

• Quicksilver Intake Manifold & Valley Gasket Set 8.1L 496 MAG | 27-881633T01
• Mercury MerCruiser Thermostat Kit 807252T5 — often serviced during intake removal
• Mercury MerCruiser Thermostat 853213001
• Mercury MerCruiser Quicksilver Thermostat 8M0045990

Service Interval

Replace whenever the intake manifold is removed — gaskets and end seals are single-use and must not be reused once disturbed. Also replace if there are signs of vacuum leaks, coolant intrusion into the intake, or oil in the valley area. Always replace the full set rather than individual gaskets to ensure uniform sealing.

Installation Notes

• Clean all mating surfaces thoroughly before installation — remove all old gasket material and sealant
• Follow the Mercury service manual for the correct gasket orientation, sealant application points, and torque sequence
• Torque intake manifold bolts in the specified sequence and to the correct specification — uneven torque causes warping and leaks
• Replace any disturbed O-rings, coolant hoses, or thermostat housing gaskets at the same time
• Pressure-test the cooling system after reassembly before returning the engine to service

Technical FAQ

Can I reuse the old gaskets if they look okay?
No. Intake gaskets are single-use. Once compressed and disturbed, they will not seal reliably. Always install a fresh set.

Do I need sealant with this gasket set?
Some end seals and corner joints require RTV sealant per the Mercury service manual. Follow the specific instructions for your engine — do not apply sealant where the manual does not call for it, as excess sealant can break off and enter the engine.

How do I confirm this is the right set for my engine?
Locate your engine's model number and serial number (on the engine block or data plate), then cross-reference part number 27-8M0073380 in the current Mercury parts diagram for your engine. If the number appears in your diagram, this is the correct set.

What are signs that the intake gaskets need replacement?
Vacuum leaks (rough idle, lean running), coolant loss without external leaks, oil in the valley or intake ports, or coolant contamination in the oil are all indicators of intake gasket failure.

Parts Desk Insights

Best use case: Any MerCruiser intake manifold removal — whether for a full engine rebuild, head gasket service, carburetor or throttle body replacement, or intake manifold replacement. This is a required consumable any time the manifold comes off. Stocking this set is recommended for shops that regularly service MerCruiser V-block engines.

Common mistakes:

• Ordering without confirming the serial number range — intake gasket sets are not universal across all MerCruiser V-block engines. Always verify the parts diagram for the specific engine serial number before ordering.
• Reusing old gaskets — even gaskets that appear undamaged will not seal reliably once disturbed. Always replace the full set.
• Skipping end seal sealant — the rubber end seals at the front and rear of the intake typically require a small bead of RTV at the corners. Missing this step is a common cause of oil leaks after reassembly.
• Incorrect torque sequence — intake manifold bolts must be torqued in the correct pattern and to spec. Random tightening causes uneven clamping and gasket failure.
• Not replacing the thermostat or housing gasket at the same time — the thermostat housing is typically disturbed during intake removal. Replace those gaskets while everything is apart.