If you are unable to find the GM RPO Codes Label, a GM dealership can usually tell you what you have using the VIN number of your vehicle. Our parts experts can also help you with identification with year, make and model information. We cannot use casting numbers for identification. Order...
Introduced in January of 2004, the RPO code LLY Duramax 6600 incorporates a number of significant technology changes. Two forces control diesel engine evolution for all engine manufacturers - Emissions compliance and market share. The technology changes introduced with the LLY address both of these ...