Between 1976 and 1982, Mercury produced 2.0-liter 150HP and 175HP two-stroke V6 outboards that featured a bolt-on cylinder head design with the head bolt pattern cast directly into the cylinder wall. These early engines, as well as the first-generation 2.4L inline V6 blocks, operate under high thermal loads and require precise gasket sealing due to their open-deck cooling systems and exposure to thermal cycling.
Original Mercury head gasket part numbers—27-79583-1, 67066, and 79583—have been discontinued and are no longer available through OEM channels. To support ongoing use of these engines, a modern replacement head gasket is now manufactured using Victor Reinz AFM 1.0MM, an advanced fiber-elastomer composite engineered for high-stress applications.
Material Properties and Performance
Victor Reinz AFM 1.0MM is a non-asbestos gasket material composed of aramid fibers and elastomeric binders bonded to a steel core. With a nominal compressed thickness of 1.00 mm (0.039"), it maintains consistent clamp load and sealing under elevated temperatures, pressure pulses, and repeated thermal cycling—common in marine two-stroke environments.
AFM material is chemically resistant to combustion gases, fuel-oil vapor, and glycol-based coolants. The steel core enhances dimensional stability and mitigates creep, helping to maintain a reliable seal even in engines subjected to saltwater exposure and long-term use.
Compared to older asbestos or cellulose-based gaskets, AFM offers significantly improved blowout resistance, thermal endurance, and material integrity. Its thermal expansion characteristics are compatible with the aluminum head and cast iron block found in these early Mercury designs, minimizing micro-movement and sealing degradation over time.
Fitment and Application
The gasket is CNC-profiled to match the original head geometry, bolt pattern, and coolant passage layout found in 1976–1981 Mercury Mariner 2.0L V6 outboards. Fitment has been validated across the full range of engines using this configuration, providing a functional replacement for all three discontinued Mercury part numbers.
Installation should follow OEM torque specs and bolt sequencing. Surface flatness and cleanliness are critical, particularly in engines with prior saltwater exposure or multiple rebuilds. Head bolts should be inspected for elongation or corrosion and replaced if necessary.
Supporting Long-Term Serviceability
This gasket restores functionality to legacy Mercury V6 platforms while introducing a more stable and durable sealing solution. By combining modern composite material with legacy geometry, it extends the service life of proven 2.0L engines built in the late 1970s and early 1980s—without requiring changes to hardware or machining.
Contact Mike Hill at +1-714-697-1716 or email mike@buckshotracing77.com for technical support.