Longer injectors 1984 and newer as i understand.  Up for sale is a set of used injection lines for a 6.2L diesel. May fit early 6.5l but i do not know that. No leaks or cracks, the truck that they came out of ran and drove fine with no issues up until the motor let go due to other problems. They're a little dirty, and you can tell that they are brand new, but they are completely unused. I bought the wrong ones and never installed. Ready to go in your project. Please feel free to reach out with any questions, thanks for looking