[HardcoreZ28]

A friend of mine gave me an old air compressor for the shop that needed a rebuild and I'm almost done with it. I have some questions about the motor on it though. He wasn't sure if it was two or three phase. Is there any way for me to look at the wiring on it and tell? My shop isn't wired for three phase so if the motor is in fact three phase would it be more economical to get a two phase motor or get a transformer for the three phase unit?