I believe that Hudson is one of the ones with 44:1 gearing. That makes for great low speed performance, but by the time you get to around 40 scale MPH, the motor is buzzing like an angry bee! I wouldn't have an issue with that top speed, but some might.
If it's like the two I recently upgraded, the Williams K4 and the Williams Niagara, the stock motor was only good for around 8,000 RPM, that gave you about 42 scale MPH. Free running with around 15 volts on it, that's as good as it got. Running at 12V (it's rated voltage), it was drawing more than an amp with no load, i.e. the wheels were suspended. I didn't have a suitable Pittman at the time, so I used a better Mabuchi 555. Same top end, but the motor was drawing around 250ma with the same 12V unloaded test.
