ACDelco Spark Plug 46XLS (GM Part #5612621)

Description:

🔧 Part Overview

• Part Number: 46XLS

• GM Part Number: 5612621

• Type: Copper core, non-resistor spark plug

• Thread Size: 14mm x 1.25mm

• Seat Type: Gasket

• Reach: Approx. 19mm (0.75")

• Hex Size: 13/16"

• Terminal: Fixed

• Electrode Material: Copper core with nickel alloy ground electrode

• Special Feature: “Fire Ring” design for enhanced combustion efficiency

• Country of Origin: Typically marked “Made in USA”

🚗 Specific Applications

The 46XLS plug was commonly used in:

• 1960s–1980s GM vehicles including Chevrolet, Pontiac, Oldsmobile, Buick, and Cadillac

• Small-block and big-block V8 engines (305, 350, 400, 454 CI)

• Marine engines (MerCruiser, OMC, Volvo Penta)

• Industrial and agricultural engines

• Vintage motorcycles and scooters requiring 14mm gasketed plugs