@@elijahinky that’s not the same. Flooring it down hill still pushes the oil to the back of the pan. There’s no inertia on a dyno meaning the hot oil pools in the front of the motor causing windage issues and aerating the oil. Air bubbles in oil is a big no no.
It's probably the dyno the portable ones are not too accurate I have a fully built 350 LT4 I hope make the same power or more good luck with your car check out one of my videos if you want to see mine.