65/66

Yup, for the most part, the above replies are correct if we're talking about an unbolt front clip. If you're talking about an innerstructure cut from the firewall forward, or, including the firewall, there a few things to take into account. I wouldn't use a '63-4 radiator core support in a V8 car. It only has an opening for a 19" radiator. The firewall on a '63 was only designed for a 6cyl and would need to be modified to accept a V8. Some of the firewall holes are a bit different over those years too.....bulkhead connector comes to mind for one. Column floor plates and shift cable holes are another.