I remember hearing a 1969 Barracuda hood would directly interchange with a 1973-1976 Dart a long time ago, though I never actually tried it so I don't KNOW it's true.

Is there any other weird interchanging that can be done...?

When I tried B body Wilwood discs on my 1969 C body front end, I found out that although my C body spindles had the Wilwood hub 1/4" farther away from the hub's base- the inner and outer bearings were the same part # and the swap was relatively easy....