In 65, the engines didn't have the vin stamped on them. This started in 68-69.   The best you could do is find a date coded engine, produced about a month or so before the build date of your car.

I am beginning what may be a needle in the haystack type of search.  I am trying to find the original engine for my 65 Sport Fury Convertible.  It was originally sold at Tom Price Chrysler Plymouth in Spokane, Washington.  It was originally white w/ white top and black interior.  It was built with a 426 wedge and 4-speed transmission.  At some point a 383 was installed and the car was painted red and the top changed to a black top.  The previous owner installed a 426 street wedge built by Marlin Bogner which is absolutely great.  He bought the car from a gentleman in Michigan several years ago.  Any help you guys can offer would be appreciated.  I have been told that engines were not numbers matched in 65 but I have also been told the opposite.  Thanks in advance and wish my luck.