[Zeke's Garage]

As long as your coolant level is full, it really shouldn't matter which hose on the heater core goes to where... but ideally, I've been told, that the pressure side from the manifold should go to the bottom of the core, and the return should go into the water pump. This keeps the core as full as possible, allowing heat transfer from the fan.

If you aren't getting hot air from the core, double check that your thermostat is installed and working. Then check the air plenum around the core, the cowl fills up with crap really fast and can choke off air flow. After that you may need to flush the core as it could be plugged and not allowing any circulation of coolant.

Good luck

Shawn