I could not say for sure,but having had both cars,I think that the 56 is not as tall top to bottom and the curve is probably different.I would doubt it could be done without doing some changes.But you can do just about anything you want to do with enough work.I think the 54 dash is cool looking.
with 56Don...- the 56 cab/dash is a diiferent beast...maybe a cut and weld if your just after the speedo look...good luck...
whether you are talkin truck or car is not clear, but in either case the main diffference is that '56 models have a wrap around windshield with the dash doing the same. The general contours of the main dash/widshield are certain similar, but the wrap around will have to be dealt with in some manner. Ray
The contour of the '56 won't bolt into a '54.A '52 or '53 dash will bolt in,if you can get a '53 dash check out these gauge panels on this ebay store New Old Parts (see pic) $245 complete with all senders and panel.Also I am sending you an invitation to the 1952-56 Ford social group just click on it and join over 290 members with '52-56 Fords to help you with your build.