A few things don't seem to add up?
Does it have 3 separate windings? i.e. 3 pairs = 6 ends?
Often a two speed motor can be two separate star connected windings, 2 pole & 4 pole.
This you can tell if you have continuity between each of 3 windings.
Star Delta usually gives the same rpm but two voltage ratings.
You need to confirm if the six ends are 3 coils not two separate star sets of windings.