Location Of Freeze Plugs On 4.0 Engine

I have a problem with coolant coming from behind the engine, between the engine and firewall, it is under the 2 a/c hoses that are routed there, my question is...is there a freeze plug located back there that could be leaking or is it a head gasket leak? so where are the freeze plug locations on this 96 explorer with a 4.0 engin ???