I could be wrong.
But depending on year (heads/cams)
The actual motors are the same.
It's the intake and ecm that make the difference.
I know all 4.6 PI engines have the same heads/cams, but the intakes and ecms are what do the difference.
IE the 99+ mustang intake and computer make the difference, because the blocks are the same, the pi heads are the same, as are cams.
Now the one thing I do not feel confident about is what year crown vic 4.6s are Windsor or Romeo. That will factor in a few other things.
But if the vic motor is Romeo, you should be golden.
The only thing is remember our 96s have a sensor in the oil pan...don't know about crown vics, but 2v mustang 4.6s from 97-04 don't so you'd need to keep your oil pan and sensor.
But 99% sure the rest is a swap in.
You may need to keep your mustang 4.6 sensors, but again not entirely sure.
But all 2v 4.6s are about the same if not exactly minus wiring harnesses, ecms, and intakes, tb, etc. But longblocks are the same.
If I am wrong on this someone who knows better will correct me.
I know alot of crown vic guys swap in mustang engines, so I see no reason why the reverse isn't possible.
1993 Mustang GT
UDPs, Smog/AC Delete, O/R H, Dumped Straight Pipes, 155lph Fuel Pump, Factory "CAI"