As in what?
I can tell you for an 81 there is.
Flare side (wood flooring) the cross members have the "U" pointing down and uses a wood block in the U to frame. There are 5 cross members all different and all of them can be replaced. They are also shorter side to side and not as tall.


The style side the "U" points up and are spot welded to the metal floor.
Are wider than the flare side and are a little taller.
I do not know if they can be replaced or not, never looked into it.


If swapping short for short or long to long it is a bolt on between the 2 bed types.
Now if doing a long to short the last 3 (gate end) bed bolt cross members line up a long with the non-bolt support cross member. It is the front cross member & support brace that do not line up and need to be worked to fit.


I know this on the 81 as I am using a LB style side metal floor in place of the flare side wood floor because just the flare side cross members were $1000 not counting anything else.




Sorry I cant be of more help on your year truck but cant see them being much different.
Dave ----