If you stay original as far as suspension they are all the same from 47-55 1st. The frame at rear wheels changed due to the bed is deeper in 54. The complete box and bed to running board aprons are different also. The rear fenders are the same. The frame over the rear wheels do not have as much arch as the 47-53. You can not use a 47-53 tail gate on a 54 bed for example. You have to change out the entire bed to 47-53 or stay with 54/551st. Hood Is the same but hood emblem and emblem location is different. Shifter rod is about 1/2" longer on 54 also or mount location changed due to dash change. Not sure if it's due to a column change as far as shifter mount location or linkage mechanism mounted to column under hood. But there is a difference in these some where. This is only valid if you planning to keep it stock. I bought a 54 for a parts truck for my 52. This is how I found these differences. Also the bell housing are different in 54 the mounting changed. From that point forward is the same.
