I am curious to discover if anyone knows the difference between the fuel tanks for the 500 XL and the various wagon models of that year and if they are interchangeable? In all of the images I have seen on various parts sites, they appear identical, and the dimensions appear the same, the biggest difference seems to be the price ($400 or so for the non-wagon tank and as low as $150 for the wagon tank). Any insights you could offer would be much appreciated.
i believe the wagon fills from the side and the xl fills from the back
Correct. And, I'm not certain about '64 models, but the 63 full-sized Fords that are not wagons were shipped with a NON-vented gas cap; there's a small tube on the upper left of the tank that connects via a rubber line to the vent line that runs up through the trunk and back down behind the bumper. Some of the photos online show that tube while others do not; tho' catalogs online or otherwise are notorious for only showing "representative" photos.
I was under mine a few months ago replacing the original rubber connection hoses with newer material that should be more resistant to ethanol-laced fuels...
1963 1/2 Galaxie 500 Fastback; 390, 4 speed "Z-code" - in the family since new