ACDelco Spark Plug R47SX (GM Part #5613884)

Description:

🔧 Part Overview

• Part Number: R47SX

• GM Part Number: 5613884

• Type: Copper core resistor spark plug

• Thread Size: 14mm x 1.25mm

• Seat Type: Tapered

• Reach: Approx. 19mm (0.75")

• Hex Size: 5/8"

• Terminal: Fixed

• Electrode Material: Copper core with nickel alloy ground electrode

• Resistor Type: Yes

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

• Special Feature: Extended tip design with green ring (on some NOS variants)

🚗 Specific Applications

The R47SX plug was commonly used in:

• 1970s–1980s GM small-block V8 engines (305, 350, 400 CI)

• Chevrolet Chevelle, Camaro, Nova, Monte Carlo

• Pontiac Firebird, Grand Prix

• Buick Skylark, Regal

• Oldsmobile Cutlass, 442

• Marine engines (MerCruiser, OMC)

• Industrial and agricultural engines

• Classic hot rods and performance builds using 14mm tapered seat heads