I had a heater hose bust and at the time i wasn't working. And the Motorcraft heater hose assembly (KH212) ranges in price from $110- $140 . They are moulded . Each having a tee with a smaller line going to intake. Long story short i put rubber plugs on heater core, water pump nipple and thermostat nipple . And looped the intake hose. Well now its cooling off and im back at work, im building my own. But my question is i cant remember which line the valve goes in. And do the arrows point towards the core or one of the 2 nipples on front. If nipples, which one. I would think the thermostat. Try not to laugh to hard at me. But its been 5 or 6 months ago and my dumb a$$ didn't take any pictures.

 

You don't need either of the smaller hoses to the intake, or the "T" hoses
And there is no "direction of flow" on the intake hoses, as long as there is one smaller hose from each heater hose coolant will flow thru

The 2 nipples on the throttle body are on one chamber to warm up incoming air when its at 0degF or less so not a Texas issue, Alaska, Northern Canada, maybe San Francisco in the Summer, lol
So leave them disconnected if you want, I would put caps on them or tape

You can use just regular heater hose no "T"s needed

Heater core has no "direction of flow", in fact you should reverse the heater hoses at the firewall every two years to back flush the core so it lasts longer, on any vehicle

Heater hose bypass valve, 4 nipples vacuum port, can be used if its not leaking, its NOT temp control
By-pass Valve is only used in MAX AC setting in the cab, it cuts off flow to heater core to reduce radiated heat under the dash, which is not nothing, but not needed if its leaking and replacement part is too expensive