Spark plugs are tiny metal cylinders that produce a spark that ignites the air/fuel mixture in your engine, generating power. These little yet crucial components form an electrical arc across two leads that aren’t touching, but close enough together that electricity may leap the gap between them.
Iridium is six times harder and eight times stronger than platinum, with a 700° higher melting point. Spark plugs with iridium electrodes have extremely fine electrodes while still having good wear characteristics. Iridium spark plugs are able to endure 25% longer than Platinum spark plugs as a result of their strength.
2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 Chevy Express Spark Plugs
| Info/Engine | 6.0L 8-cyl Engine L96 Flex | 6.0L 8-cyl Engine LC8 |
| OEM spark plug gap | 0.040″ (1.01mm) | 0.040″ (1.01mm) |
| Qty. needed | 8 | 8 |
| Change interval | 97,500 miles | – |
| Best spark plug | NGK 1465 IZTR5B11 Laser Iridium Spark Plug | NGK 7397 TR5IX Iridium IX Spark Plug |
| Popular choice | Denso 5090 ZTJ16R10 Iridium Long Life Spark Plug | NGK 1465 IZTR5B11 Laser Iridium Spark Plug |
| Info/Engine | 6.6L 8-cyl Engine L8T | 4.8L 8-cyl Engine L20 Flex |
| OEM spark plug gap | 0.040″ (1.01mm) | 0.040″ (1.01mm) |
| Qty. needed | 8 | 8 |
| Change interval | – | 97,500 miles |
| Best spark plug | Champion 9777 RES14WMPB4 Iridium Spark Plug | NGK 1465 IZTR5B11 Laser Iridium Spark Plug |
| Popular choice | Champion 9777 RES14WMPB4 Iridium Spark Plug | NGK 3784 PTR5D-10 Laser Platinum Spark Plug |
| Info/Engine | 4.3L 6-cyl Engine LU3 | 5.3L 8-cyl Engine LMF |
| OEM spark plug gap | 0.060″ (1.52mm) | 0.040″ (1.01mm) |
| Qty. needed | 6 | 8 |
| Change interval | 97,500 miles | 97,500 miles |
| Best spark plug | NGK 5599 ITR4A-15 Laser Iridium Spark Plug | NGK 1465 IZTR5B11 Laser Iridium Spark Plug |
| Popular choice | NGK 7164 TR55IX Iridium IX Spark Plug | NGK 7397 TR5IX Iridium IX Spark Plug |
| Info/Engine | 4.3L 6-cyl Engine LV1 |
| OEM spark plug gap | 0.040″ (1.01mm) |
| Qty. needed | 6 |
| Change interval | 96,000 miles |
| Best spark plug | NGK 91418 ILTR5E11 Laser Iridium Spark Plug |
| Popular choice | NGK 4344 LTR5IX-11 Iridium IX Spark Plug |
2003 2004 2005 2006 2007 Chevy Express Spark Plugs
| Info/Engine | 5.3L 8-cyl Engine LM7 | 4.3L 6-cyl Engine LU3 |
| OEM spark plug gap | 0.040″ (1.01mm) | 0.060″ (1.52mm) |
| Qty. needed | 8 | 6 |
| Change interval | 100,000 miles | 100,000 miles |
| Best spark plug | NGK 1465 IZTR5B11 Laser Iridium Spark Plug | NGK 5599 ITR4A-15 Laser Iridium Spark Plug |
| Popular choice | NGK 7397 TR5IX Iridium IX Spark Plug | NGK 7164 TR55IX Iridium IX Spark Plug |
| Info/Engine | 6.0L 8-cyl LQ4 Engine | 4.8L 8-cyl Engine |
| OEM spark plug gap | 0.040″ (1.01mm) | 0.040″ (1.01mm) |
| Qty. needed | 8 | 8 |
| Change interval | 100,000 miles | 100,000 miles |
| Best spark plug | NGK 1465 IZTR5B11 Laser Iridium Spark Plug | NGK 1465 IZTR5B11 Laser Iridium Spark Plug |
| Popular choice | E3 E3.54 Spark Plug | NGK 3784 PTR5D-10 Laser Platinum Spark Plug |
1997 1998 1999 2000 2001 2002 Chevy Express Spark Plugs
| Info/Engine | 4.3L 6-cyl Engine L35 | 5.0L 8-cyl Engine L30 |
| OEM spark plug gap | 0.060″ (1.52mm) | 0.060″ (1.52mm) |
| Qty. needed | 6 | 8 |
| Change interval | 100,000 miles | 100,000 miles |
| Best spark plug | NGK 5599 ITR4A-15 Laser Iridium Spark Plug | NGK 5599 ITR4A-15 Laser Iridium Spark Plug |
| Popular choice | NGK 7164 TR55IX Iridium IX Spark Plug | NGK 7164 TR55IX Iridium IX Spark Plug |
| Info/Engine | 5.7L 8-cyl Engine L31 | 7.4L 8-cyl Engine L29 |
| OEM spark plug gap | 0.060″ (1.52mm) | 0.060″ (1.52mm) |
| Qty. needed | 8 | 8 |
| Change interval | 100,000 miles | – |
| Best spark plug | NGK 5599 ITR4A-15 Laser Iridium Spark Plug | NGK 3951 TR55 V-Power Spark Plug |
| Popular choice | NGK 7164 TR55IX Iridium IX Spark Plug | NGK 5599 ITR4A-15 Laser Iridium Spark Plug |
GM OE (Professional) Iridium Spark Plugs are the most up-to-date variant of spark plug technology. The high melting point and strength provided by the iridium composition of the spark plug helps to improve wear resistance and durability.
So, should you replace spark plugs with coil packs? It is debatable. The most frequent component to change in conjunction with the ignition coils is the spark plugs. Spark plugs that have been worn out can put an excessive strain on the coils and there may be some overlap in the tasks needed to switch both parts.
