3V COLD SPARK PLUG SET (12MM THREAD)

The 3V COLD SPARK PLUG SET (12MM THREAD) is an essential performance upgrade designed for engines running higher than stock cylinder combustion pressures or experiencing sustained high rpm usage. These plugs provide a cooler operating range to ensure optimal combustion efficiency and help prevent pre-ignition under extreme driving conditions.

Key Features

One heat range colder than stock Mustang GT and 5.4L-3V truck spark plugs
Engineered for high-pressure or sustained high-rpm environments
Sold complete in an engine set of 8 spark plugs
Premium construction ensuring reliable spark delivery

Fitment

Fits 2008 and newer 3V heads requiring the 12 mm thread
All 2009-2010 3V engines requiring a 12 mm spark plug

Note: 2008 engines with late-style 12 mm spark plugs can be identified by coil engineering number 8L3E. For early style 2005-2008 3V heads with 16 mm "High Thread" design (identified by coil engineering number 3L3E), use part number M-12405-3V0 instead.