A buddy of mine who has a friend of his who works at Navistar told him that in a few years GM will not be using Isuzu motors anymore they are going to use international motors. They may still call it the duramax but it wont be isuzu making it. Since i highly doubt both ford and GM will use the same motor block i wonder what they have in store for the GM's. . Hopefully a inline 6 motor. .