I assume you mean the cab?
AFAIK the main difference will be in the cab mounts.
Plus 2 more years of rust! wink

The 48 would have used a 3-point,whereas the 50 4-point mounts.
I'm sure somebody will be along soon to confirm this and any other subtle differences.

1950 Chevy Advance Design 3100 in Scotland
In the Stovebolt Gallery
More pix on Flickr.
I've definately got this truck thing in my blood ... my DNA sequence has torque settings
"Of all the small nations of this earth,perhaps only the ancient Greeks surpass the Scots in their contribution to mankind" Winston Churchill.