1968 Ford Mustang Heater hoses

Hello
Thanks for the donation.

To better assist you, could you please post the 8th VIN for your vehicle.

Thanks for that info. Below is a diagram of the hoses.

Typical A/C and heater vacuum hose diagram routing

I have here as well, the instructions of removal/installation for the heater assembly.

REMOVAL/INSTALLATION:
Disconnect the battery and drain the coolant.
Disconnect the heater hoses at the engine.
Loosen the screws at the choke housing and move the hose out of the way.
Remove the nuts retaining the heater to the dash.
Remove the screw retaining the ground wire at the dash and disconnect the two wires. Remove the glove box liner.
Disconnect the defroster hoses, temperature control cable, defroster control cable, and heat control cable.
Remove the screw retaining the heater to the air intake.
Remove the heater assembly from the vehicle pulling the hose through the dash.
Install in the reverse of above

Heater assembly mounting on 1964-1969 models:

I hope this helps. Let me know if you need anything else.

On the 1968 there are two hoses one a little bigger than the other. With the previous owner disconnecting them and bypassing the heater. The small hose connects to the bottom of the heater core and the larger to the top. The reason for this is that larger one fills the coil faster than the bottom one lets it out slowing it so the heater core can extract the heat. On the heater core you will notice a different inlet size you can use as reference. The connections one is by the thermastat and the other by the water pump. These also are diferent sizes that can be used to correspond the hooking up of hoses.