I have a '46 Chevy 6400. When I got it , the original 235 had no governor and it would occasionally get the speedometer up to 60. A year later, I was replacing the engine (chewed-up crank) with a '53 factory replacement that had the governor in place. It will get the speedometer up to 50, my wife was following me once in her car and said I was doing 54. That's as fast as I would want to go in the old beast and I'm not sure if I would want to hold it there for a long period of time.
