Brian; some things will fit between the 63-9 Americans, some won't. I have a 65 440 and I bought a 68 220 post. I used some of the interior in my 65. What I have found is that from the door sill down, they will fit. Hdtps and converts will interchange (kinda) and 4-drs and wagons will interchange (kinda). Different options will interfere with each other. I have a 68 dash in my 65 and it bolted up. The door mechanisms swapped out. The nice chrome headliner trim did not except for about half of them. All in all, you need to be specific about what pieces you are talking about. If you are after 64 parts I came across a 440 that was seriously T-boned and the guy is parting it out. I forgot his number but will post it tommorrow....Russ