The way I understand it, Zero off would need to be a new motor for 05. It's the ECM that is the issue, you need what is called eControl I believe, I do not have the correct ECM for Zero Off in my 07 197 so I have decided to just wait to upgrade boats. I heard some late 07s had the eControls, but I think they came in all of the 08 tournaments teams. Don't quote me on that.