Help!

Has anyone ever blown a freeze plug on a 12a engine? does anyone know the normal location of the plugs and will they blow if there isn't enough antifreeze in the radiator?

I had a rx7 w/ a 12a shipped from California and it was shipped with water and water wetter in the radiator!!

When I put antofreeze in the radiator now(should have tried water first, I guess) it leaks out on to the floor just behind the front axle(center of the case). Is there a freeze plug(s) there? It looks like at the lowest part of the case before the transmision.

Thanks,

Bruce