Their are many differences. But if your just trying to change over to the 4.1 trans. From what I have gathered and ordered. I went on Ebay and just bought a whole new one including the new t-plate. 40 bucks. Gonna start with 3000wt diff oil. But for every little detail that they changed around as many have said before its just as easy to spend 100 bucks more for a complete kit! As for me I went the cheaper hopefully easier way!