I'm on my 3rd, going on 4th ax15 and to my knowledge there is no better tranny for my application. Toyota has basically the same tranny in some of their trucks. I heard that the internals are stronger on the toyota model Aisin ax15 tranny. I know that it is not a direct swap due to the input and possibly the output shaft. Does anybody know if an internal swap is possible and if it is what does it entail? Or if possibly there is a better tranny for my application? I was considering the nv3550, but for the strength increase, I don't believe that it is worth it. I would like 6 speed tranny with the shifting smoothness of the ax15 and the strength of an nv 3550. If any body can help me out with some knowledge or some good websites I would appreciate it.