Most any A-body buckets will swap over , as far as the fit . Some of the patterns will vary . But they'll be a direct bolt-in . My 66 Dart is using buckets from a 1995 Neon , so you can think outside the box some also .
Got a 65 GT with the slant . Gonna be a parts car . Never tried to fire it , but it does crank . Complete . Auto trans can go too . Still in car . PM if interested .
That about sums it up on early VIN's . 1st digit , Dart /6 . 2nd digit , Dart GT . 3rd digit , 1963 . 4th digit , Los Angeles Ca built . Last 6 digits is the sequence number . Thats it .