dyno day for the demon

moper said
HP is calculated off torque so one would expect if one got that much better the other would show more.

Good point moper. The easy math shows 519 torque to be 375 horses... at 3800 rpm! Up that to 4000 which would be reasonable as torque peak and you are at 395hp... something doesn't add up here. Or is't a very "peaky" engine.