Look at the Id take on the front cover ,take the engine sir # and call Cummins.The tag will also say what year ,cpl # ,
If it doesn't have a ID take ,look in this section and you'll see a few 12V pics.
89-98 are easy to hook up ,but will need more info from you and also what are you working on.
The engine and trans wil depend on what you plan on using ,auto or stick .
Scott