water pump flow direction

If you're running a magnum timing cover and pump with a v-belt and pulleys from an LA, you're spinning it backwards...
Magnums run a serpentine drive and spin the pump opposite an LA, if I remember correctly.(and if I'm wrong someone here WILL correct me...).

I wondered if that was possible but don't have the specific knowledge.
If it flows the other way, then does the thermostat have to be different somehow?