64 Barracuda gas tank options?

A friend of mine put a Mustang tank in a 70 Duster that he installed a spring relocation kit on, and put the gas cap in the tail panel. It worked fine, but the gas cap looked like Fidos *** in the tail panel. You might measure a tank for a B body, to see if it is narrow enough and not too long. Then you could make the filler hide behind the license plate. I have a 25 gallon tank that I had made for my Duster, when I was going to put a 5.7 Hemi in it, but it is heavy as hell and may be too wide for an early A.