ACDelco Spark Plug R42LTS6 (GM Part #5613904)

$34.99

type: Unknown Type
Vendor: CorvairFarmer

Description:

🔧 Part Overview

  • Part Number: R42LTS6

  • GM Part Number: 5613904

  • Type: Copper core resistor spark plug

  • Thread Size: 14mm x 1.25mm

  • Seat Type: Tapered

  • Reach: Approx. 17.25mm (0.670")

  • Hex Size: 5/8" (16mm)

  • Terminal: Fixed

  • Electrode Material: Copper core with nickel alloy ground electrode

  • Gap: Typically 0.044"

  • Heat Range: 2

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

  • Marine Use: Yes – compatible with MerCruiser and other marine platforms


🚗 Specific Applications

The R42LTS6 plug was commonly used in:

  • 1982–1983 Cadillac 4.1L V8 engines (DeVille, Eldorado, Fleetwood, Seville)

  • GM small-block and big-block V8s across various platforms

  • Marine engines (OMC, MerCruiser, Volvo Penta)

  • Industrial and agricultural engines

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