NOS AC R45TS Spark Plug – GM #5613884

Description:

🔧 Part Overview

• ACDelco Part Number: R45TS

• 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

• Gap: Typically 0.044"

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

• Special Features: Ribbed suppressor seal, Black Onyx coating for corrosion resistance2

🚗 Specific Applications

The R45TS plug was widely used in:

• 1970s–1990s GM vehicles, including:

  • Chevrolet Camaro, Caprice, Chevelle, Nova, Monte Carlo, C/K Series trucks

  • Pontiac Firebird, Grand Prix

  • Oldsmobile Cutlass, 442

  • Buick Regal, Skylark

  • Cadillac Brougham, DeVille

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

• Marine engines: MerCruiser, OMC, Volvo Penta

• Industrial and agricultural engines

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