I did some more research and I think it's a Muncie 318 (four bolt side cover)I'll go with the consensus and stick it in and see how it goes. I took a real good look again and I see the teeth are really worn on one side of the narrow gear in the center (1st/Rev?) I read somewhere that it could be reversed and used again. I can't see the one in the back very good so I don't know the condition. Anyway, Button it back up and keep an eye out for a used one.
