Early-ish half ton Dodge WC. Code on the engine will probably be T207 or T211 if you clean it. Frank is right about the dual wheels. I don't think this was a dual wheel unit from the factory, as the Maintenance trucks and the like ( that had factory duals ) had helper springs on the back axle and some had fishplated chassis strengthening - don't see either here.
The chassis number, from the front left chassis rail side, will lead you to a Build Card that will tell you exactly what it started as and the date it was built.