My only experience in pylon was sitting in the cage and calling cuts for Quicky 500, Q-40, and F-1 classes. Most of the F-1 flyers had hand carved wooden props small enough to let the engines turn 24-28K. Those diameters and pitches I quoted were ball-park guesses to make the point about how a prop's dia/pitch is determined by the airplane's task.
F-1 is no longer an AMA class.

You are probably right about the speeds, if they really went 200 mph, they would finish the 2.5 mile race in 45 seconds. Typical winning times are in the 1:04 range.

I think they did away with the cages too. Now they call cuts from the sidelines.