I know about being able to modify the AC 300 for 2X, 4X, and 4X locked positions. Does any one know if the models that use the same style diff. could have parts added to make them capable of the locking position. I'm pretty sure that just repositioning the lever would not do it because I tried that on an autocat 500 when they first came out at my local dealer. I think there must be some parts that have to be added to the diff.