Blower fan motor no A/C

[truckin 79]

I just replaced my blower fan motor in the 79, it started squealing like a pig in the cold. The thread about missing blower motor resistor got me thinking. Is this blower motor a 3 speed or 2 speed motor? I sprayed out plug to resistor because it was pretty dirty. Well when I cleaned it the fan motor only comes on 2 speed low and high. In low speed the new motor wines a little. When I turn radio on does not really bother me. I was just wondering if I go back to parts store and try and see if I can get a quieter one or if all fan motors in low sound this way.
Thanks