Are both vehicles the same transmission configuration?
Off the top of my head:
Transmission Harness (if auto)
Skinny pedal (fuel by wire on the PSD).
If you can find a complete donor truck, this is probably the best option. You'll be able to figure out exactly what you need with a little work tearing into both trucks.
If that isn't an option, some International applications (namely the DT444E in school buses) have s standalone computer mounted on the valve cover that will make the swap easier than putting it together piece by piece.
The list above is in no way complete. Never done the swap myself, just helped friends along with theirs.
Last edited by backwoodsboy; 10-08-2012 at 12:03 AM.