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Vehicle Info NeededMSD IGNITIONPART NUMBER: 121-3712
Iridium Spark Plug Heat Range: 5
$1083
Ships on Sep 14, 2026
Lowest Price Guarantee5/8" Hex Tapered Seat.691 Reach
- Iridium Spark Plug
- Heat Range: 5
- Extended 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.
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Features:
- Optimized for High Power Engines
- Iridium Strength
- Yttrium/Copper Core
Part TypeSpark Plug
Product LineMSD Iridium Spark Plugs
BrandMSD IGNITION
Package Height2.0
Package Width2.0
Package Length4.0
Weight0.1 PG
Part CategoryPerformance Parts
Part FitmentSemi Universal
Vendor Part Number3712
Package Qty1
Package TypeEA
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