It depends on how big the trailer is, and where you are pulling it. If the trailor isn't real big and heavy, your not pulling it through the mountains, and you keep O/D off on the tranny whenever you are going uphill, you should be ok. But now, keep in mind since the car is 10 years old, if the tranny is on it's last leg, so to speak, pulling a trailor might just be enough to finish it off.
Are they both 4.6 L ?
The 1997 Ford Crown Victoria owners manual shows ( 5 w 30 )
No, I doesnt fit. Check the tail of the 1997 and there is a speed sensor. The 2003 doesnt have it.
In a 1997 Ford Crown Victoria : Fuse ( # 16 ) is a 20 amp fuse for the cigarette lighter
I was looking at the drawings of the instrument panel ( gauge cluster ) in the 1997 Ford Crown Victoria Owner Guide and it doesn't have a factory tachometer
A 1997 Ford Crown Victoria engine is fuel injected so there is no carburetor
You can see the blueprint of the door on a 1997 Grand Marquis/Crown Victoria at the related link below. This will aid in the removal of the panel.
The 1997 Ford Crown Victoria OBD 2 port is located under driver side dash next to center console