It's interesting, we're talking about someone trotting out the old Harley engines remade with today's tooling.
I remember reading a biography on WWI combat pilots and some of the best were also serious motorcycle riders. None were Harley riders - that's not the point, but the riders were noted for "Roaring around the roads on their Wanderer or Moto Reve" and you look at the bikes they look less powerful than a bicycle. Heck they look like bicycles.
I'm guessing that new Harley engine would be similar - slow, dull, and dangerous to operate.