As others have said, looks like you have a 1965 series 289 block. Just above and slightly to the left off the C in C5AE you will find a number followed by a letter and 1 or 2 numbers. This will give you the actual casting date (so 5A3 would be January 3rd 1965). That would tell you the precise date. "289" may also be cast into the valley between the lifters to confirm if it's a 289.
As a tip, if you do want to buy parts from US look for (or ask seller) if they participate in Ebay's Global Shipping Programme or have an Ebay shop. I shipped a pair of 65 (iron) heads from US to UK for my Mustang and although it takes a little longer was only $80 more than shipping to a friend in Miami as Ebay ship in bulk. They may not ship something as heavy as a block but worth keeping in mind for other stuff.
Good luck with your restoration.