When the engine is cold, start the engine, let it idle and turn up the heat to maximum. Whichever hose gets warm first is on the in side and the opposite one will be the out side.
OK
Now on the firewall the upper hose has the heat control valve, I figure thats the input to the core and the hose directly under that one is the output.
Heater was not putting out much heat.
I back flushed the heater core, had it hooked up to the garden hose.
Now it puts out whole buncha lottsa heat!! :thumbsup: