Seat Back Stops allow your seat back to be adjusted and sit right. The plastic upper stops contact the plates on the seat. #607A will work on any 1957 Chevy 2-Door model.
Note: Car seats are often swapped over the years and the seat in your classic may not be the correct one for your model year. If your seat stops are cut on an angle with an oblong hole in the center that contacts a metal stop on the seat back you have a 1955-1956 seat in your car. You will need 1955-1956 seat back stops #607 and #903.