I highly doubt anything from the two motors fit each other. The warrior cases would have to be bored to fit the larger jug, and new bolt holes would have to be made in order to bolt the xt head/jug to the warrior case. The issue here is that you can't just put a bolt anywhere in the case, since it has to be able to hold a certain torque spec for the head bolts, and not interfere with anything. The only reason it is even possibly though is that the timing chain is on the left side of both motors. Also, the counterbalance in the warrior engine would probably need to be changed as I can only assume the 600 has a heavier piston. This is pretty much a dream right now to have a Yamaha Warrior 600, but maybe one day I'll actually try it lol.