Hi Craig I have a 1/3hp Westinghouse with 5/8" keyed shaft. I salvaged it from the house my son bought in merritt - the people who sold it just left everything. The old fellow was a tinkerer and I hauled about 15 motors home that the kids were gonna haul to scrap. I don't want anything for it but I'm not sure how to get it there. We are going in August if you're not in a rush.
B
I think ⅓ hp won‘t be adequate. I have a ½ hp on my 9” SB and it is about right. The SB also doesn’t have any headstock gears to eat up power.
Have you disassembled your existing motor? Replacing a bearing or two shouldn‘t be too difficult.
If you go with a replacement make sure it is capacitor start. It takes a bit of torque to get things moving.
I have a 1/2hp 3 phase motor. 5/8x2” keyed shaft Maybe theres a vfd in your future?
Smaller ones like those used in furnace fans don't have capacitors. They don’t have much starting torque.