Sometimes I think the guys you get to talk to from Deere just plain lie, and other times I think they don't have a clue what they're talking about. A 72" on an X?!? They'd have to either really stretch the frame, or the deck would have zero overlap on the blades, and even designed with no overlap I don't think that it would fit under the machine between the front and rear wheels. I know how large the 72" is for my 4115 CUT, and no way that'd fit under the X frame/wheel base as currently designed. Years ago, many of the smaller Deere CUTs used a 2 cylinder Yanmar diesel engine. I don't see why they couldn't use a modernized version of one of them in the 900 series frame and make it all work.