Another Heater Core ?

Hello all,
To replace the heater core in my 75, do I have to pull the whole heater out? What is the best way to go about doing this. Thanks.

 

You have to pull the box that the core is in. It isn't all that hard. First drain system and disconnect the heater hoses. You then need to CAREFULLY disconnect the oval shaped hose leading from the cowl air box. You won't find another one of those if you damage it. It is also stapled as well as clamped to the cowl box, so you want to disconnect the end from the main heater box. Then disconnect your control cables and unplug fan wires. There is if I remember right about 4 nuts under accessible from under the battery box under the hood, that hold the box to the firewall. There should also be a drain hose leading from the bottom of the box through the firewall. You also need to unhook your defroster hose. Then you should be able to remove the box, then the core from the box. I might add that you can see what you are doing better if you first remove your glove box. It is held in place by 6 to 8 screws.