Thanks a lot! You are right- it is a two speed motor. This is what I was thinking and probably what I will do based on your comments and others here. This is just a hobby for me and I rarely run faster than 2000rpm. I think my old round column tops out at 2500 and I am afraid to run it that fast.
I recently purchased a Jet JTM-1 (Bridgeport clone) step pulley mill. It is 3 phase and I don't have 3 phase at my house. I am going to purchase a VFD from Amazon to get 3 phase and take advantage of changing speeds with the twist of a knob. I do have experience with this as I have already done...