AC Delco 41-101 Iridium Spark Plug | GM 4.3L V6 & MPI Marine Engines | Replaces MerCruiser 33-8M0204739, NGK ITR4A15, Crusader RP030010 Equivalent | GM Z30600115 | OEM Replacement | Sold Individually

AC Delco 41-101 Iridium Spark Plug — GM 4.3L V6 & MPI Marine Engines | Replaces MerCruiser 33-8M0204739, NGK ITR4A15 & Crusader RP030010 Equivalent | GM Cross-Reference Z30600115 | OEM Replacement | Sold Individually

AC Delco 41-101 is an iridium spark plug used as OEM equipment in GM 4.3L V6 and related MPI marine engines. Replaces MerCruiser 33-8M0204739 and is the AC Delco iridium equivalent of the NGK ITR4A15 (NGK 5599) for the same applications. GM internal cross-reference: Z30600115. Sold individually — order the quantity needed for your engine.

Part Specifications

• Part Number: AC Delco 41-101
• SKU: ACD-41-101
• Plug Type: Iridium
• GM Cross-Reference: Z30600115
• Replaces (MerCruiser): 33-8M0204739
• Replaces (NGK): ITR4A15 (see also: NGK 5599 ITR4A15 Laser Iridium Spark Plug)
• Replaces (Crusader): RP030010 individual equivalent (see also: Crusader RP030010 Platinum Spark Plug Kit 8-Pack)
• OEM Status: OEM iridium replacement for GM MPI marine engine applications
• Sold As: Individually (single plug)

Cross-Reference & Replacement Guide

• MerCruiser 33-8M0204739: The 41-101 is the AC Delco iridium replacement for MerCruiser 33-8M0204739. Verify this is the correct plug for your specific MerCruiser engine model and year in your service manual before ordering.
• NGK ITR4A15 (NGK 5599): The 41-101 is the AC Delco iridium equivalent of the NGK 5599 ITR4A15 for the same GM marine engine applications. Both are iridium plugs — choice comes down to brand preference.
• Crusader RP030010: The Crusader RP030010 is an 8-plug kit. The 41-101 is the individual AC Delco iridium equivalent. Verify the cylinder count and Crusader engine model before ordering by quantity.
• GM Z30600115: GM internal OEM part number that cross-references to the AC Delco 41-101. If your parts documentation lists Z30600115, order the 41-101.
• Not interchangeable with other AC Delco plugs in this catalog: The 41-983 (GM 8.1L, platinum), 41-993 (GM 6.0L V8, iridium), and 41-110 (GM LS-series, iridium) are different plugs for different engine families. Confirm your engine’s specification before ordering.

Compatible Marine Engine Applications

Verify against your engine service manual or existing plug part number before ordering:

• MerCruiser 4.3L MPI V6 marine engines: The 41-101 / MerCruiser 33-8M0204739 / NGK ITR4A15 are used in MerCruiser 4.3L MPI stern drives. Confirm the correct plug for your specific model year in your MerCruiser service documentation.
• Crusader engines using RP030010: Crusader engine configurations for which the RP030010 8-plug kit is specified. Verify the individual plug specification and cylinder count for your Crusader engine model before ordering.
• Other GM MPI marine applications cross-referencing 33-8M0204739 or NGK ITR4A15: Any marine engine manufacturer using a GM MPI block that cross-references to these part numbers may use the 41-101. Confirm against your engine documentation.
• Verify before ordering: The 41-101 is an iridium plug. Confirm your engine specifies iridium and that 41-101 is the correct part number for your model and year.

Iridium Plug — Installation & Service Notes

• The 41-101 is pre-gapped — verify the gap specification for your engine in the service manual before installation; do not re-gap with standard gapping tools as the fine-wire iridium tip can be damaged by contact with the tool
• 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 — many OEM iridium plug installations do not require anti-seize; over-application on aluminum heads can cause torque errors
• Sold individually — order the quantity matching your engine’s cylinder count (6 plugs for a V6 engine; 8 plugs for a V8)
• Change at the interval specified in your engine service manual; do not extend iridium service intervals beyond the manufacturer’s recommendation in a marine environment

Additional Information

• Vendor: AC Delco
• SKU: ACD-41-101
• Part Number: 41-101
• GM Cross-Reference: Z30600115
• Replaces: MerCruiser 33-8M0204739 | NGK ITR4A15 | Crusader RP030010 (individual equivalent)
• Product Type: Boat & Engine Maintenance / Spark Plugs
• Plug Type: Iridium
• 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 41-101 replace MerCruiser 33-8M0204739?
A: Yes — the 41-101 is the AC Delco iridium replacement for MerCruiser 33-8M0204739. Verify this is the correct plug for your specific MerCruiser engine model and year in your service manual before ordering.

Q: Is the AC Delco 41-101 the same as the NGK ITR4A15?
A: Yes — the 41-101 is the AC Delco iridium equivalent of the NGK 5599 ITR4A15 for the same GM marine engine applications. Both are iridium plugs; either can be used based on brand preference.

Q: How many plugs do I need?
A: Order the quantity to match your engine’s cylinder count — 6 plugs for a V6 engine or 8 plugs for a V8. This listing is for one (1) individual plug. The Crusader RP030010 8-pack is available if you need a pre-counted kit.

Q: Is the 41-101 the same as the 41-983, 41-993, or 41-110?
A: No — the 41-983 is a platinum plug for GM 8.1L engines, the 41-993 is iridium for GM 6.0L V8, and the 41-110 is iridium for GM LS-series engines. The 41-101 is for GM 4.3L V6 MPI and related applications. None are interchangeable.

Q: What is GM part number Z30600115?
A: Z30600115 is the GM internal OEM part number that cross-references to the AC Delco 41-101 iridium spark plug. If your engine parts documentation or dealer lookup shows Z30600115, the 41-101 is the correct AC Delco replacement.