I had read that the original Otadama motor put out big HP numbers but the physical size of the motor was too big for the frame they had planned. Sounds like if they went with that motor it would have been the size of a Boss Hoss.
i actually heard it wasn't so much a different motor but basically different heads with variable valve timing that got in the way of the frame..which is all over the top of the motor now..... story is we still may see it down the road as a special addition or race kit