Iridium Spark Plug Heat Range: 5
Product Discontinued
MSD IGNITIONPART NUMBER: 121-3721

Iridium Spark Plug Heat Range: 5

Currently Unavailable

This product is no longer available. Please call customer service for assistance at 1-800-345-4545.

5/8" Hex Tapered Seat
  • .437 Reach
    • Iridium Spark Plug
    • Heat Range: 5
    • Non-Projected Tip
    • 1/pkg

    • Proprietary plug design inside and out
    • Designed for use on high performance vehicles that utilize high output ignition systems
    • Machined electrode increases exposure to the flame to improve combustion
    • Yttrium ground electrode reduces the chance of pre-ignition
    • Iridium tip improves cold starts
    • All spark plugs tested prior to packaging and shipping

    Delivers Twice the Power

    MSD Iridium Spark Plugs are designed with a premium yttrium/copper core for maximum durability which represents ultimate spark plug performance and technology. Iridium is six times harder than platinum, which reduces the voltage requirement for a spark.

    Show More

    Features:

    • Optimized for High Power Engines
    • Iridium Strength
    • Yttrium/Copper Core

    Spark Plug Heat Range Explanation, Click Here

    Part TypeSpark Plug
    Product LineMSD Iridium Spark Plugs
    BrandMSD IGNITION
    Package Height1.0
    Package Width1.1
    Package Length3.5
    Weight0.09 PG
    Part CategoryPerformance Parts
    Part FitmentSemi Universal
    Vendor Part Number3721
    Package Qty1
    Package TypeEA
    No Questions
    No Reviews

    Items You Need

    Spark Plug Holder Holds 16 4-Pack Boxes

    PIT PAL

    Spark Plug Holder Holds 16 4-Pack Boxes

    Part Number : 777-829
    $8899

    ITEM YOU MAY ALSO CONSIDER

    Spark Plug Suppressor

    AUTOLITE

    Spark Plug Suppressor

    Part Number : 417-145
    $399
    Some parts are not legal for use in California or other states with similar laws / regulations
    p65 warning
    Your Cart

    Your shopping cart is empty!