I think pulling the post back on a 48-51 makes the nose look to long. I'll leave mine straight and cut the roof from door to door, and pull the post toward each other a 1/2 inch. then put a strip back in the middle. The back window will be mail slot. About 5" tall in the middle. That's taking out 5" of the top. Plus this way you don't have to pull the door post back.