Welcome to the forum and great to see another '64 galaxie here too! Not to mention one that's been in the family since the '70s! I've had mine since 77.
Don't have anything in mine but the all natural AC which was a little toasty when we were living in the desert.
Lots of knowledge here so ask away and also do some searches here for info before you ask as it might of been covered before at one time or another.
Deb