If you decide to rewind, make sure you go to a quality shop that has rewound these motors before. The older motors had resets built into the motor,or in some cases, did without, and could use simpler switches. You MUST have overload protection installed. The new motors are not overload protected, they rely on overload protection from the switch assembly.
Depending on the switch installed, you may have to install the new GPE style switch. If you want to change out this motor, you will need the new 3450 RPM motor, a new motor pulley ( it’s smaller) and a new set of belts(they are shorter). I see a lot of these motors still in use in old lumber yards. This is plenty of power for the home woodworking shop.
The oversize, five and one half inch motor pulley overdrives the arbor to a speed of 3000 RPM or so. Even though these motors were rated at only one to one and one half horsepower or so, they developed a LOT of torque. If you have this motor, and are changing it because it is fried, I would seriously consider re-winding it. Earlier unisaws used a large, one or one and one-half horsepower motor running at 1500 to 1725 RPM. Luckily for me, my unisaw works fine with the motor that is in it- but I found this on the web, thought it was interesting. I'd appreciate any size and brand recommendations, as well as any cautions. I really like the one-button convenience (no RPC to turn on), power-loss safety feature, and overload protection the VFD would provide. Also, would the braking feature of the VFD harm the motor? I see limited application of variable speed, but it would be fun to play with, to a point. I'm hopeful that a run-of-the-mill VFD at the bottom of the price spectrum will do the job. That seems to indicate that I should be alright, but I want to make sure. My main concern is longevity of the motor. Retrofitting a modern or standard motor requires either butchering the saw's cabinet or modifying the motor and mounting bracket. (They were known as "bullet" motors for their shape.) A single phase bullet motor was available but command a premium on the used market. The motor was purpose built by Marathon Electric just for these saws. I've come into an old (early '60's) Delta Unisaw very cheap.