The only real difference is in the holes that the emblem fastens to the hood though. Someone else is going to have to explain the difference but it amounts to one or the other emblems won't swap directly over to the other hood.
Here is a 54 hood that I had setting on my 48 before I sold the hood to a local guy building a 54.
That was just laying on my truck and as the truck had been put though the wringer as a daily driver for 15 years nothing fits right front end wise.
If you have your old hood you might take the emblems off and compare the holes and go from there.