Autolite 766 Spark Plug

Autolite 766 Copper Resistor Spark Plug

Autolite 766 is a copper resistor spark plug built for quick starts, steady ignition performance, improved fuel economy, and smooth acceleration. It is an OE-style replacement for select 1983 Ford and Mercury applications, including Ford F-100, LTD, Mustang, and Thunderbird, plus Mercury Capri, Cougar, and Marquis.

Key Features

• Copper center electrode core for reliable spark transfer
• Nickel center and ground electrode tip materials
• 5000 ohm resistor for ignition noise suppression
• 0.044 in. / 1.10 mm pre-gap size
• Tapered seat with 14 mm thread diameter and 0.679 in. / 17.0 mm reach
• Mid-projection ceramic insulator for standard ignition service
• 5/8 in. hex size with stud terminal type

Product Details

The Autolite Copper Resistor Spark Plug line focuses on OE form, fit, and function for foreign and domestic vehicles. Part number 766 uses a standard regular center electrode design, a single ground electrode, and nickel-tipped electrodes to support consistent combustion in everyday driving. For 1983 Ford F-100, 1983 Ford LTD, 1983 Ford Mustang, and 1983 Ford Thunderbird applications, as well as 1983 Mercury Capri, 1983 Mercury Cougar, and 1983 Mercury Marquis, this plug matches the listed tapered-seat configuration and factory-style dimensions.

This part cross-references AP Exhaust 7545 and AWSF52 for the same application.

Common Issues This Part Can Address

• Hard starting caused by worn spark plugs
• Rough idle from inconsistent ignition output
• Reduced throttle response during acceleration
• Ignition noise concerns in resistor-equipped systems
• Maintenance replacement for aging OE-style plugs

Installation Notes and Tips

Verify the 14 mm thread diameter, 5/8 in. hex, tapered seat, and 0.044 in. pre-gap before installation. Confirm the vehicle uses the listed 1983 Ford or Mercury application and follow the manufacturer’s service procedure for torque and gap verification. Autolite 766 is a direct-fit style spark plug for the specified engines and ignition setups.

Quality Assurance

Autolite supplies ignition products to the automotive aftermarket and original equipment manufacturers, and this copper resistor spark plug follows OE-style fitment and functional requirements for the listed applications.