Bob, I would recommend you take measurements of the area you want to install the tank and then do an ebay search in the auto parts section for gas tank. Many of the auctions will include outside dimensions you can compare to those you wrote down. Once you identify a tank that will fit you can then look around the local yards. The ones off ebay will probably not come with the sending unit which you will need. If you are using a mechanical fuel pump you will not want a tank with an in-tank fuel pump as those are intended for fuel injection type motors. If that is what you are running then the options available to you increase.
I used an 18 gallon tank from a 67-69 camaro on my 54. Others recommend the blazer 31 gallon tank. If a camaro tank will fit for you I know of one in Wabash some old man has. You can probably talk him out of it pretty easily. Right Popcorn!
