Welcome to DPFexhaust Diesel Resource Center. Whether you're upgrading performance parts or installing emissions upgrade components, identifying the exact diesel engine in your truck is the first and most important step.
This guide explains how to identify the most common Duramax, Cummins, and Powerstroke engines using your VIN number, build date, and engine codes.
If you are still unsure which engine you have, contact DPFexhaust support team to help verify your engine using your full VIN number.
GMC / Chevrolet / Duramax
The Duramax diesel engine family has evolved through multiple generations since its introduction in 2001. While the engines share similar architecture, many components such as injectors, turbochargers, ECM calibration, and sensors differ between generations.
Using Your VIN Number
The easiest way to identify your Duramax engine is by checking the 8th digit of your VIN. This digit indicates the engine code.
| Model Year | Engine | 8th digit of VIN Code |
|---|---|---|
| 2001 – 2004.5 | LB7 | 1 |
| 2004.5 – 2005 | LLY | 2 |
| 2006 | LLY | 2 |
| 2006 – 2007 | LBZ | D |
| 2007.5 – 2010 | LMM | 6 |
| 2011 – 2016 | LML | 8 |
| 2011 – 2016 | LGH (Van) | L |
| 2017 – Current | L5P | Y |
VIN Example
Example VIN numbers:
-
1GCHK29143EXXXXXX → LB7 Duramax
-
1GCHK29245EXXXXXX → LLY Duramax
The 10th digit of the VIN identifies the vehicle model year, which can help confirm the engine generation. The example above shows the 2003 LB7 and 2005 LLY.
Dodge / Ram / Cummins
The Cummins diesel engine used in Dodge and Ram trucks is one of the most recognized diesel platforms in North America.
Locate Your VIN Tag
Your VIN tag is typically located on the driver-side door jamb. This tag includes:
-
Vehicle build date
-
CPL (Certified Parts List) number
-
Full VIN number
Cummins Engine Variants
| Engine | Model Years | Identification |
|---|---|---|
| 5.9L Cummins | 2003 – 2004 | Build date before 12/31/2003 and/or CPL # 8213, 8228 or 8412 |
| 5.9L Cummins | 2004.5 – 2007 | Build date between 01/01/2004 – 01/01/2007 and/or CPL # 8346, 8347, 8350 or 8351 |
| 6.7L Cummins | 2007.5+ | Build date after 1/1/2007 |
Identify between 6.7 Cummins Pickup vs Cab & Chassis
If your truck does not have a factory pickup bed, it is likely a cab & chassis model, which uses different engine calibrations and performance parts.
If you're unsure, contact us to verify your configuration with your full VIN number.
Ford / Powerstroke
Ford’s Powerstroke diesel engines have undergone several major updates since the 1990s.
To find your VIN, check the driver’s side dashboard (visible through the windshield) or your registration/title.
Powerstroke Engine Variants
| Model Year | Engine | 8th digit of VIN Code |
|---|---|---|
| 1994-2003 | 7.3L Powerstroke | F |
| 2003-2007 | 6.0L Powerstroke | P |
| 2008-2010 | 6.4L Powerstroke | R |
| 2011+ | 6.7L Powerstroke | T |
Final Thoughts
Correctly identifying your Duramax, Cummins, or Powerstroke engine ensures you purchase the right performance parts for your truck.
If you need help confirming your engine configuration, contact us at service@dpfexhaust.com.
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