1970 Dart Swinger Heater core Removal
Pretty much as described by pa340dart, but I seem to recall there's one nut closer to the center of the firewall that supports the end of the heater box as well. Don't forget to remove the defroster duct hoses, the clips are a real pita, but they should come off the box outlets pretty easily. Once you get the box out, then you simply remove the spring clips and it splits. I recommend at least trying to get as much coolant out of the core as possible as it will end up on your carpet when you are turning the box to remove it. If you've never done it before it will probably take you about 2 hours or less to remove it. As for the long hook through the right side vent, you simply loosen the 5/16 head bolt on the bottom of the vent area and swing the rod away from the cowl top.