AC Delco 41-983 Platinum Spark Plug | GM 8.1L Marine Engines | Replaces MerCruiser 33-863622001, Crusader RP030009, NGK PZTR5A-15, PCM RP030009, Marine Power 810E-210 & Volvo Penta 3861326/3861327 | Sold Individually

AC Delco 41-983 Platinum Spark Plug — GM 8.1L Marine Engines | Replaces MerCruiser 33-863622001 (33-8M0129146), Crusader RP030009, NGK PZTR5A-15 & TR55IX, PCM RP030009, Marine Power 810E-210 & Volvo Penta 3861326/3861327 | Sold Individually

AC Delco 41-983 is a platinum spark plug used in GM 8.1L (496 cid) marine engines across MerCruiser, Crusader, Marine Power, PCM, and Volvo Penta inboard and stern drive applications. Replaces MerCruiser 33-863622001 (updated: 33-8M0129146), Crusader RP030009, NGK PZTR5A-15 and TR55IX, PCM RP030009, Marine Power 810E-210, and Volvo Penta 3861326 and 3861327. Sold individually — order the quantity needed for your engine (the GM 8.1L is an 8-cylinder engine).

Part Specifications

• Part Number: AC Delco 41-983
• SKU: ACD-41-983
• Plug Type: Platinum
• Replaces (MerCruiser): 33-863622001 / 33-8M0129146 (updated part number)
• Replaces (Crusader): RP030009 (see also: Crusader RP030009 Platinum Spark Plug Set 8.1L)
• Replaces (NGK): PZTR5A-15 (see also: NGK 7862 PZTR5A-15 Laser Platinum Spark Plug) and TR55IX
• Replaces (PCM): RP030009
• Replaces (Marine Power): 810E-210
• Replaces (Volvo Penta): 3861326 and 3861327 (see also: Volvo Penta 3861326 Spark Plug 4-Pack Platinum)
• Primary Application: GM 8.1L (496 cid) marine engines
• Sold As: Individually (single plug) — order 8 plugs for a GM 8.1L V8 engine

Cross-Reference & Replacement Guide

The 41-983 consolidates part numbers across multiple marine engine manufacturers that all use the GM 8.1L block. If your engine currently lists any of the following plugs, the 41-983 is the AC Delco replacement:

• MerCruiser 33-863622001 / 33-8M0129146: The 33-863622001 is the original MerCruiser part number; 33-8M0129146 is the updated supersession. Both are replaced by the 41-983. This is the OEM plug for the MerCruiser 8.1L Horizon inboard engine.
• Crusader RP030009: The 41-983 is the individual plug equivalent of the Crusader RP030009 Platinum Spark Plug Set for the 8.1L engine. Order 8 individual 41-983 plugs as the equivalent of the 8-plug set.
• NGK PZTR5A-15 and TR55IX: Both are NGK alternatives for the same GM 8.1L marine application. The NGK 7862 (PZTR5A-15) is available individually in this catalog. The TR55IX is the NGK iridium variant — the 41-983 is the platinum equivalent; confirm which specification your engine manufacturer requires.
• PCM RP030009: PCM (Performance Center Marine) uses the same RP030009 part number as Crusader for the 8.1L application. The 41-983 is the AC Delco replacement for both.
• Marine Power 810E-210: Marine Power uses the GM 8.1L block in their inboard engine lineup. The 41-983 replaces the Marine Power 810E-210 plug specification.
• Volvo Penta 3861326 and 3861327: The 41-983 replaces both Volvo Penta plug part numbers used in GM 8.1L-based Volvo Penta inboard configurations. Note: Volvo Penta 3861326 also appears as a cross-reference for the AC Delco 41-993 in 6.0L applications — verify which part number your specific Volvo Penta engine model and year requires before ordering.

GM 8.1L Marine Engine Applications

The GM 8.1L Vortec (496 cid) is a large-displacement V8 used in high-horsepower marine inboard and stern drive applications by several manufacturers:

• MerCruiser 8.1L Horizon (496 cid): High-output inboard engine used in cruisers and large performance boats. OEM plug: MerCruiser 33-863622001 / 33-8M0129146, replaced by 41-983.
• Crusader 8.1L MPI and MP8.1: Crusader inboard engines based on the GM 8.1L block. OEM plug kit: Crusader RP030009 (8-plug set), individual equivalent: 41-983.
• Marine Power 8.1L: Marine Power inboard engines using the GM 8.1L block. OEM plug: Marine Power 810E-210, replaced by 41-983.
• PCM 8.1L: Performance Center Marine inboard engines based on the GM 8.1L block. OEM plug: PCM RP030009, replaced by 41-983.
• Volvo Penta 8.1L GXi / OSi: Volvo Penta inboard engines using the GM 8.1L block in their GXi and OSi series. OEM plug: Volvo Penta 3861326 / 3861327, replaced by 41-983.
• Verify before ordering: Confirm the 41-983 is the correct plug for your specific engine model, year, and horsepower rating. Check your engine service manual or the existing plug part number before ordering.

Platinum vs Iridium — Which Plug Does Your 8.1L Require?

• The 41-983 is a platinum plug. Marine engine manufacturers specify either platinum or iridium for the GM 8.1L depending on the engine series and model year — do not substitute an iridium plug for a platinum specification or vice versa without confirming the OEM requirement in your engine service manual.
• The NGK TR55IX (also listed as a cross-reference above) is an iridium variant for similar applications. If your service documentation specifies TR55IX, verify whether platinum (41-983 / PZTR5A-15) or iridium (TR55IX) is the correct specification for your engine.
• The AC Delco 41-110 and AC Delco 41-993 are iridium plugs for different GM marine engine families (LS-series and 6.0L V8 respectively) and are not interchangeable with the 41-983 for the GM 8.1L.

Application Notes

• Sold individually — the GM 8.1L is an 8-cylinder engine; order 8 plugs for a full tune-up. The Crusader RP030009 plug set is available if you prefer a pre-counted kit.
• Verify the correct gap specification for your engine in the service manual before installation
• Thread in by hand for the first several turns to avoid cross-threading; torque to the specification in your engine service manual
• Apply anti-seize only if specified by your engine manufacturer
• Change at the interval specified in your engine service manual; marine operating conditions (high load, heat, and humidity) may warrant shorter intervals than the stated maximum

Additional Information

• Vendor: AC Delco
• SKU: ACD-41-983
• Part Number: 41-983
• Replaces: MerCruiser 33-863622001 / 33-8M0129146 | Crusader RP030009 | NGK PZTR5A-15 / TR55IX | PCM RP030009 | Marine Power 810E-210 | Volvo Penta 3861326 / 3861327
• Product Type: Boat & Engine Maintenance / Spark Plugs
• Plug Type: Platinum
• Primary Application: GM 8.1L (496 cid) marine engines
• Sold As: Individually (single plug)
• Country of Origin: USA
• HS Code: 8511.10 (spark plugs — verify for your import classification)

Frequently Asked Questions

Q: Does the 41-983 replace MerCruiser 33-863622001?
A: Yes — the 41-983 replaces both the original MerCruiser 33-863622001 and its updated supersession 33-8M0129146. This is the OEM plug for the MerCruiser 8.1L Horizon inboard engine.

Q: How many plugs do I need for a GM 8.1L engine?
A: The GM 8.1L is an 8-cylinder (V8) engine — order 8 individual 41-983 plugs for a full tune-up. The Crusader RP030009 plug set is also available as a pre-counted kit for the 8.1L.

Q: Is the 41-983 a platinum or iridium plug?
A: The 41-983 is a platinum plug. Use it only in applications where platinum is the OEM specification. If your engine documentation references the NGK TR55IX (iridium), confirm whether platinum or iridium is correct for your specific engine model and year before ordering.

Q: Does Volvo Penta 3861326 cross to the 41-983 or the 41-993?
A: Volvo Penta 3861326 appears as a cross-reference for both the 41-983 (GM 8.1L applications) and the 41-993 (GM 6.0L applications). Verify the correct plug for your specific Volvo Penta engine model and year in your engine service documentation before ordering either plug.

Q: Is the 41-983 the same as the AC Delco 41-993 or 41-110?
A: No — the 41-993 is for GM 6.0L V8 marine engines (Crusader 6.0L MP, Volvo Penta 5.7L/6.0L GXi/OSi), and the 41-110 is for GM LS-series marine engines (MerCruiser Gen V 4.5L/6.2L, Volvo Penta V8-300/350/380). The 41-983 is specifically for the GM 8.1L (496 cid). None of these are interchangeable.