I've been just sitting back to see what others thought about this motor. It's a nice piece but the stock 5.8 crank simply can't handle the prop. These were industrial equipment motors in stock form with pretty massive flywheels but they were more centrally located than our props allow. Brison eventually made an overhung crankshaft with a better mounting surface but they are long gone.

ive been trying to convince my son to just sell this motor or park it and get a more modern 80-85 motor. Even selling the entire P51 would be better and maybe build a new one around a rear exhaust or an inline twin.

thanks for the input.