I also had one hell of a time finding a heater core for my 67 non a/c 400 bird. I ended up getting a core that was the right size from AMC off ebay and then putting my tanks and tubes on it. Of course after I did that I found a web site that has what looks to be the right heater core. www.rockauto.com You might take a look and see if it looks right to you. Good luck!