Which way does the thermostat face in a 93 Ford Ranger 3.0 V6 long end up or down?

There's no "up" or "down" orientation specifically mandated for a 1993 Ford Ranger 3.0L V6 thermostat housing. The thermostat itself sits inside the housing, and the important thing is that the thermostat is installed correctly within the housing, ensuring proper coolant flow. The housing itself will have an orientation determined by its mounting points on the engine. There's no ambiguity as to how it mounts to the engine block or intake manifold. The only crucial aspect is the correct installation of the thermostat *inside* that housing.