motor question

I just picked up a nice Berger stepper or server motor at my local
salvage yard. It does not have a model label on it.

Does anybody out there know how I can identify it? It has three
electrical connections 1, 2, 3 and a frame ground connection. It is a
NEMA 34 size 3.25X3.25 and is 6.75" tall (this includes the box that
covers the electrical connections).

I don't know whether it's a stepper for servo. I assume it's a
stepper because of the # of wire connections and the lack of feedback.

Anything you can tell me about how to identify it is much appreciated.

Doug