Fitting the doors to the door openings is one of the most difficult things to accomplish on a full-frame car like a 1955-57 Chevy. It's not as easy as adjusting just the door hinges! This rare guide published by Fisher Body in 1957 is a huge help when perfecting the gaps on you tri-5. Note the range of acceptable gaps is 1/16" to 3/16" on the top and sides of the doors. Can you imagine anyone today being happy with a 1/16" door gap? The lower gap range is 1/8" to 1/4"!