WHICH OF THE HOSES TO THE HEATER IS THE SUPPLY TO THE HEATER IS IT THE ONE FROM THE TOP OF THE WATER PUMP OR THE ONE THAT COES UP FROM DOWN BELOW ON THE PASSENGER SIDE

 

WHICH OF THE HOSES TO THE HEATER IS THE SUPPLY TO THE HEATER. IS IT THE ONE FROM THE TOP OF THE WATER PUMP OR THE ONE THAT COMES UP FROM DOWN BELOW ON THE PASSENGER SIDE

 

The hose coming from the passenger side head.

 

so which side is it? in this thread they say that it's return line to the block? https://www.ford-trucks.com/forums/1...ater-hose.html

 

The hose connected to the WATERPUMP is the HEATER RETURN and the hose connection at the PASSENGER SIDE HEAD is the HEATER SUPPLY.
The hoses cross at the rear of the engine.
At firewall connections (when facing):
WATERPUMP =Left side
PASS HEAD = Right side