I was reading the thread by the guy that wants to borrow calipers for a powder coating job.

There were a few questions I had about this and wanted to get clarification without mucking up his thread any further.

Do the 4.4 and 4.6 calipers interchange without modification?
Do they have more/different pistons/ surface area?
Can either be used on a 3.0?
Can you use the same rotors, or are they different?
Do you different (larger) wheels to clear them?

I am no stranger to break swaps (I have C5 corvette calipers and rotors on my firebird) and it helps to know these things right before you are doing something like a brake job on a 70k mile car.