We do not know the dimensions of your brushed motor so unfortunately, we are not able to answer your first two questions or your last question. We can provide the dimensions of our brushless motors though so you can check them against the dimensions of your brushed motor and see if they are the same size.
Our 48 Volt 1600 Watt and 60 Volt 2000 Watt brushless motors are both the exact same size and their dimensions are; 106mm wide x 135mm long excluding shaft and 160mm long including the shaft.
Please let us know if you have any questions.
William Salazar