is there a flow in and a flow out line on the heater core hoses in the engine bay? for example...is the top hose for fluid from the engine to flow into and the bottom hose for fluid from the heater core to flow into the engine?

 

Yes sort of.. When installed the fluid flows in one side and out the other. The direction doesn't really matter though. It would work either way.

 

cool...i knew one was in and one was out, but didn't know how it flowed in a normal rx-7...like is the top in and the bottom out? oh well...i'll find out