RPS Iridium Spark Plugs for Mercruiser Volvo Penta PCM Indmar 5.0/5.7/6.2 V8 — Set of 8, Direct-Fit Replacement

If you own a Mercruiser, Volvo Penta, PCM, or Indmar-powered boat with GM-derived 5.0, 5.7, or 6.2 engines, these RPS iridium plugs provide a direct-fit replacement that preserves factory specifications. They’re sold as a set of eight, match the AC Delco 41993 footprint and are designed for fuel-injected marine ignition systems. Built with an iridium center electrode for longer life and consistent spark performance, they’re a practical service item for seasonal tune-ups and mid-life maintenance.

Will these plugs fit my Mercruiser 350MAG or 5.0MPI engine?

Yes — these RPS iridium plugs are compatible with Mercruiser 350MAG and 5.0MPI engines from 1997 and later, including models listed under Black Scorpion and other factory variants. They match Mercruiser part references and mounting parameters for a bolt-in replacement.

• Fits Mercruiser 350MAG and 5.0MPI (1997+)
• Direct compatibility with Mercruiser part 33-8M2018369
• Sold as a set of 8 plugs for V8 applications
• Maintains original plug reach, thread size, and heat range

How do these plugs compare to AC Delco 41993 or OE parts?

RPS plugs are manufactured to match the form, fit and function of AC Delco 41993 and other original-equipment references, so they can be used as a like-for-like replacement. The iridium tip offers longer service intervals than standard copper plugs while retaining the correct thermal characteristics for GM 5.0–6.2 engines.

• Equivalent to AC Delco 41993 in dimensions and spec
• Iridium center electrode for extended life and stable spark
• Engineered for fuel-injected ignition timing and performance
• Meets OEM thread and seat specifications to prevent leaks

Which Volvo Penta and PCM engines accept these spark plugs?

These plugs fit a range of Volvo Penta and PCM GM-based engines beginning in 1997, covering 5.0 and 5.7 GXI/GI family engines as well as several 6.2 variants. Cross-references include Volvo Penta part numbers cited by manufacturers for direct replacement scenarios.

• Compatible with Volvo Penta part numbers 21467472 and 3858996
• Fits Volvo Penta 5.0 and 5.7 GXI/GI (1997+)
• Works for PCM and Indmar installations using GM-based V8s
• Appropriate for fuel-injected marine engine calibrations

What should I expect during installation and maintenance?

Installation is straightforward for anyone familiar with marine V8 ignition systems: remove the old plugs, check threads and sealing surfaces, torque the new plugs to the manufacturer’s specification, and route boots properly. Regular inspection during annual service ensures optimal performance and longevity.

• Install using manufacturer torque specs to avoid over-tightening
• Replace in complete sets for even combustion across cylinders
• Inspect ignition boots and coil packs while plugs are out
• Recommended for scheduled maintenance every season or per hours

Who is this for? Boaters, marine mechanics, and DIY owners running GM-derived 5.0, 5.7, or 6.2 fuel-injected marine engines who want a durable, OE-equivalent iridium replacement. If you need parts compatible with Mercruiser, Volvo Penta, PCM, Indmar, or AC Delco 41993 specifications and prefer the longer service life of iridium electrodes, this set of eight RPS plugs is a practical choice for routine tune-ups and performance-minded maintenance.