I don't know how accurate the AutoZone system is, but I've always had good luck with RockAuto.
Here's the link to their listing of the part specifically for your 63'.
https://www.rockauto.com/catalog/x,c...,parttype,7418
If you do go with RockAuto, always google "RockAuto Discount Code" and you'll save yourself 5%.
Conversely, you could always buy the AutoZone part and return it if it isn't the correct one...