I heard the same Eddy. Seems the stroke is what the problem is so they compensated for that 40 years ago by making the inline 3 and 4 cylinders. With the double overhead cams you can compensate for stroke limitations but then you have bore issues and heat transfer problems with the super wide jugs. Anyhow 4 decades ago they abandoned the super big P-twin idea. They called it a Trident.
That concept drawing looks a lot like this.
