Hey windy, remember your building the truck for you, not for anyone else!

Having said that I think the newer dashes might be too deep and make the tight cab tighter (that and I dont care for the 90's dashes much), Maybe a 79 or older dash, not as deep and steel so you can narrow it easier? Or how about grafting in just the instrument cluster from another vehicle? I have my 48 f-47 next to my 60 falcon parts car, the instrument cluster keeps calling to me for a test fit.

Scott

 

Link didn't work, try this one;

Wilder Street Rods main

 

or WWW.whyitwontwork.duh

 

Be aware that the 56 dash is a structural element, thus it is a welded in place assembly. A majority of late model dash assemblies are a metal framework with a lot of plastic skin panels hung on it. Pretty difficult to find plastic to steel welding rod these days to join the two.
I don't know if your donor has airbags or not, but if it does and they have not been removed or activated, you are dealing with a couple hand grenades with the pins out. Activated unexpectedly (easy to do when removing) they can kill.
That all said, the person here that others have mentioned (not Keith) that did a similar swap used the donor floor pan, firewall and dash as a unit and grafted the older sheetmetal onto the outside. No word on if it ever was finished, most frame swaps never get past the "cab is set in place..." stage. Good luck.